dfj240

iTrader: (1)

Hey guys, I'm new to the forum, but I've been stealing all of your killer info to help me out for the past week or so with my new-to-me Maxima. I picked up the car with a multitude of issues, all but one of which I have been able to solve. I'm a pretty capable mechanic, but I'm not an expert or a professional. In any case, down to business;

Vehicle in question: 2002 Maxima SE 6-Speed 169k

Installed new intake manifold gaskets yesterday, including the upper plenum gasket -- Helped my idle problem

I just installed a new MAFS today. 22680-2Y001 from a 2001 Maxima and used my original Air temp thermistor -- Solved my idle problem.

The car wouldn't idle at all before I changed the IM gaskets, it would just die. I've got it idling pretty smooth now, HOWEVER...

When I put my foot down on the throttle more than approximately 50-55% (according to my freeze data), it bogs and bumbles along. No VQ glory at all! Under light load, it will accelerate fine, but if you try to drive spiritedly at all, forget it. List of all that I know to have been changed.

MAFS - Brand New from Dealer
IM Gaskets
2 Coils - Previous Owner replaced two on the front for some reason and no others
Spark Plugs - All are NGK-R's, and seem to fire just fine though I can't be sure they have been changed. --Probably my next course of action.
Injectors looked clean - Sprayed them with MAFS cleaner while I had the manifold off for good measure.

I have also let the car idle and sprayed MAFS cleaner near/on all the vacuum lines/intake seals to see if the revs picked up any (that's how I determined my IM upper plenum gasket leak) with no luck finding anything.

Any one have any ideas? I've searched this site and google for any kind of answer and most of the time it points to a MAFS, which I've already done, so I'm pretty befuddled at the moment. Only thing I can think of would be coils or maybe the plugs aren't firing like they should under heavy load.

MIL (SES) Code is P0300 - Random Multiple Misfire (The common one I gather)

Thanks in advance for your aid. Cheers.

-Nathan

Edit: Just ran the part number of the plugs and they are standard copper NGK's. OEM Plugs are Double Platinum per my information (My information is usually rubbish). So I assume that some mildly worn copper plugs aren't going to generate quite enough spark to satisfy the fuel demand of the VQ. Am I right in the assumption? Cheers.

dfj240

iTrader: (1)

UPDATE: Changed out the plugs to the NGK Double Platinum's that are supposed to be in it, and it helped a little bit. The car picks up a little better, but under a good amount of load it is still very sluggish. Under no load it revs just fine, but under load it doesn't have much to give. Any help is very much appreciated, as I'm not quite sure how to proceed.

I'm planning on taking the car to the local Nissan dealer tomorrow or Monday to have the ECU reprogrammed and the Idle relearned, but I get the feeling that will not completely remedy my problem. I'll keep this thread updated as I make progress. Cheers.

-Nathan

036mtmax

iTrader: (11)

Coilpack

dfj240

iTrader: (1)

I plan on testing them all tomorrow to make sure they're all within spec. I'll share my results.

After constant research all friggin day, I am interested to hear what you all think about the P0300 code being caused by;

A) Bad head gasket between the cylinders
B) Camshaft has lobes that have become flat
C) Battery/Alternator
D) O2 Sensors

These seem a bit odd to me, but, at the same time, I can see how they would possibly have some effect. Please keep the ideas coming. I know some of you have solved this before, and I'd love to be in that group.

-Nathan

Alright well, I left my multimeter at the shop so I couldn't test all the coils, but I was able to determine (by doing the unplugging test) that the coil in cylinder 3 was no good. I changed it out for a brand new one today, and just like everything else, it helped a little bit more.

I also tested the battery and it wasn't putting out proper voltage, so it too has been replaced. Oddly, that seemed to help a tiny bit as well.

I feel like I'm really close here. Part of the reason I feel that way is because prior to replacing everything that I have so far, the SES light would blink and then stay on. Then it got to where it would blink, and stay off, blink, stay off, blink, and then stay on. Now the SES light will only blink when the ECU detects the P0300 condition, but does not feel it necessary to leave the SES light on. It simply logs a ghost code, and carries on. It blinked on about 7 or 8 different occasions on my way home this evening.

A little more info that might help you all possibly help me is that the car is running very rich. Also, the car will idle well, and even drive decently now (albeit without much power), as it's warming up. At N.O.T. it will bog down, and, most of the time, die when pulling up to a light/stop sign unless I heel-toe to keep the revs up.

So to run through the list again:
Coils - 3, 4, and 6 are brand new; 1, 2, and 5 are yet to be voltage tested, but seem to be ok.
Battery - New
Alternator - Tested Perfect
MAFS - New (2001 from dealer)
Plugs - New (NGK Double Platinum)
IM gaskets - New
VIAS - Opens Power Valve just fine; yet to be voltage tested
PCV - Purchased, haven't replaced yet, will replace tomorrow
o2 Sensors - Seem to be within spec according to the OBD2 data readout, but I suppose if it could be causing the issue, I can remove and clean/replace them.
Injectors - Yet to be voltage tested; Will test tomorrow.
All vacuum lines checked for leaks - Replaced two
Intake system sprayed down with MAFS Cleaner/B12 - No change in revs on any seal

I have not been able to get the ECM Mode II Reset Procedure to work properly, nor have I been able to get the Idle Relearn Procedure to work. I believe I'm doing something wrong. Anyways, I'll keep plugging away and update again tomorrow. If anyone has any helpful tips or places to look, please let me know. Thanks. Cheers.

-Nathan

Amave

test your oxygen sensors , using your multimeter tap into the signal wire and ground anywhere on the engine or neg. battery terminal, the switching rate when it is hot should be instantaneously , you should see the voltages jump from .1v up to 1.0v and back down again, i have seen a dead or lazy o2 sensor cause driveability issues , because if it is sending the wrong signals to the ecu, the ecu will dump fuel due to poor signal ( or no signal ) or take away fuel .

If it is dumping fuel when you accelerate, then i could see how it could bog due to a rich condition .


Also do you see black smoke from the tail pipe when you hit the gas hard?

dfj240

iTrader: (1)

Excellent. I was definitely curious about that. Thanks for the tip. I will test them out today, and, seeing as they all still have the little Nissan logo, leading me to believe they are all factory o2's, I will probably just change them all to be safe.

No smoke of any kind from the tail pipe under any condition though. During the drive back from picking the car up, my mate told me that there was a tiny bit of black smoke when I would accelerate, I knew this was because of how extremely rich it was running, so I wasn't too bothered by it, and it has now ceased smoking at all. I'm getting close. Lol. Thanks for the specs to test those o2's with. I'll definitely give it a shot. Cheers.

-Nathan

Amave

no problem man, but you should test them before replacing just so you can see the switch rate of the sensor.

IIRC the signal wire is the white wire, you should see the volts move at idle somewhat slow and as you rev the engine the numbers should shoot up to 1.0v and back down to .1v, this is normal operation of the sensor , like i said since the multimeter is an almost real time tool ( which means as soon as voltage goes down and up, it registers the reading ) so if the sensor stays at any voltage for more than 1-2 seconds, then it is either dead or lazy ( both of which will cause a problem )


Good luck and let us know what you found

dfj240

iTrader: (1)

Alright, got around to voltage testing today. o2 sensors checked out to be ok.

Three of the coils have been replaced to this point. They all checked in at 1.6** or thereabouts (Correct range for a good coil). All three others that haven't been replaced (Cylinders 1, 2, and 5) tested at 1.118, 1.112, and 1.113 respectively. The one's that were replaced were all known bad coils as well. Now the question is, should I be looking at something besides the coils specifically that might have caused them ALL to fail, or is it possible, they were just all bad? I've seen 2 or even 3 fail at once, but I've never seen a situation where every single one of them were all bad.

I already put in an order for 3 replacement coils, and should get them sometime this week, so when I do, I'll toss them in there and see how she does. The injectors all sound good as well (Nice *click*click*click* sound that they should make). I will update when I get the new coils installed and take her for a test drive. Thanks for the help Amave. Cheers.

-Nathan

Amave

yeah coils on our cars do go bad, even more than 1 at a time .

ECU is the only thing that tells them when to fire, i can't think of anything else that would cause them to go bad other than the coil themselves

dfj240

iTrader: (1)

Ok good. I don't think the guy who had this car before me knew what he was doing. He definitely knew how to keep a car clean, but this thing had a lot of running issues when I picked it up from him. It's all getting sorted out, and she's in good hands now. I'll take the time to clean it up to a nice shine and post some pictures when I get it running well. Thanks again for the help mate.

-Nathan

Alright, the car now has all brand new coils and a new pcv valve AND..... No change! Still bogs down under heavy load around 3k and will not rev past 4k unless I feather the throttle past that. So, now I'm really running short of ideas. Any help would be much appreciated.

Still no code besides P0300. Is it worth it, even after all the parts I've replaced to take the car to the stealership and have them at least run a diagnostic with Consult II? I think it'll run me somewhere in the neighborhood of $100. Is that right? Is it worth it?

snicklefitz

depends on if you have the hundred dollars to spend, would be worth it to me just to know whats wrong with the car....maybe dont go to the stealership and try a local mechanic first, if your not satisfied then go to the stealer....i took the g/f's car to the stealer just to give her piece of mind even though i pretty much told her what was wrong....made her happy lol

EuroDriver

iTrader: (21)

Maybe the fuel strainer is clogged up and when you accelerate hard, the fuel flow becomes restricted. However, the ECU reset and idle relearn should definitely be done after replacing the MAF (from what I have read).. Did you get that done yet?

dfj240

iTrader: (1)

Well, called the dealer and they said it's $110 PER HOUR for Consult II! Although, I did talk to rather knowledgeable service adviser who instructed me to check the ECU to make sure there is no water or sediment on the connection. He said the ECU sealing on these cars isn't particularly great and it would be a good idea to disconnect it, spray it down with the some electrical contact cleaner and let it dry out for a while, and see if that helps.

He said he had a 2003 maxima that had the same exact issue I was describing and they were trying to figure out for weeks before they went to remove the ECU to test it and there was water inside the plug. They let it dry out, plugged it back in, problem solved. No more P0300 code.

Oh, and no, I haven't had the chance to go get that done. I was going to do it this week, but we were backed up at the shop quite a bit and didn't get any free time during the dealer's service hours to take it up there. You think that the relearn and reset will solve it? possibly? Lol. Thanks for the help, and I will check the fuel strainer and filter. Thanks again.

-Nathan

cjandura

iTrader: (3)

I would not spray anything in the ECU if anything remove cover and let air dry under a fan.

dfj240

iTrader: (1)

So don't even spray it with that CRC electrical contact cleaner on the plug? Fair enough. I'll pull it out and let it dry for a day or so to be sure it's fully dry. The car doesn't have to be driven right away anyways. Has anyone else ever experienced this issue before though? It's a first for me hearing about the possibility. My car was purchased from auction by the previous owner with the same issues, which makes me wonder if it could have been a flood car perhaps.

In any case, I will update when I make a little more headway. Thanks again. Cheers.

-Nathan

RR5

iTrader: (6)

It's not the same thing but the principle would still apply to the ECU.

This is from a computer certification book, 2006:
Use denatured alcohol to clean electrical contacts and
components such as the drive heads on removable media drives.

Obviously, test the cleaning agent in some other location and see if anything remains when it dries.

tosheto

iTrader: (5)

Replace fuel filter (cheap item).
Do you regularly scan the codes? Any new codes?
Are your coils new aftermarket or OEM?

Amave

now that i think of it, do our cars have an external TPS sensor?

I have seen the resistance go up when ohm testing TPS sensors on other cars that would bog under load ( due to the ECU getting incorrect readings from the TPS )


Might try that if you can ...


Take a nulti meter and set it to ohms, then connect the leads in series and move the TPS sensor ( slowly ) and look for any breaks in the multi meter readings

EuroDriver

iTrader: (21)

Spraying electrical cleaner will be fine - that's what it's designed for. Just disconnect your battery, wait a few minutes, and make absolutely sure it dries out before reconnecting ECU harness & battery.

dfj240

iTrader: (1)

Alright, to answer some questions/suggestions...

Fuel filter is inside the pump, and I'm definitely going to look into that. If I can just go ahead and buy a replacement pump with the filter already pre-installed, so I don't have to go through the extra work of dismantling the pump just to change the filter, then I'm going to go that route. So I will definitely look at that.

I check the codes every time I drive the car and shut it back off, to make sure I don't have any odd/random/different ghost codes or anything like that. I have a Cornwell Handheld OBDII Scanner, so this is easy for me to do. The ONLY code I have ever received is the P0300 Random/Multiple Misfire.

All 6 coils are brand new OEM. And they have been resistance tested (even though they're new) just be sure they're perfect. They are all in good order.

The TPS is electronically controlled by the electronic throttle input at the accelerator pedal. I suppose you could still test it by leaving it attached to the throttle body and just move the butterfly open and closed manually, though I'm not 100% that it would work. However, the TPS should trip a code if it's malfunctioning enough to not allow the car the throttle position that is being requested by the accelerator.

Good to know on the electrical cleaner, I figured a good light spray down would at least help a little to take care of any possible corrosion that might try to build up. And I plan to leave it disconnected to dry for at least a couple hours. It's not my only means of transportation, so I'll be fine without it if I have to go somewhere for any reason.

Thanks for the help and suggestions guys. Here's my plan of attack:

+ Disconnect ECU and let it dry if need be.
+ Fuel Pump or Fuel Filter replacement.
+ Headers - Because, hell, maybe it's a clogged pre-cat. If it is, this should solve my problem, if it's not, I've just avoided a potential problem. Win-win.
+ Retest all the injectors (just to be sure)
+ Test TPS
+ Test Accelerator throttle connection

And if none of that works, it's going to the dealer, unless someone can give me another suggestion on where to look. Consult II Diagnostic will run me $110 per hour, but, as far as I've narrowed it down already, I don't think it will/should take more than an hour. Anyways, pardon me while I go look for a killer deal on some headers. 8)

Thanks again for the help guys. Just having a new place to look makes a world of difference. Very much appreciated. Cheers.

-Nathan

Alright, a little update, I drove the car today. My brother was in town so I decided to hang out with him and show him the Maxima. I was able to disconnect the ECU today and inspected it and even left it disconnected for several hours, but everything looked perfect to me, and there was no change when I reconnected it. I didn't think it was the issue, but it was an easy possibility.

Anyways, I did notice that the car lurches when changing gear and the revs drop more rapidly than they should. The car also has a problem stopping the rev drop at idle, and will die most of the time when I push the clutch in, unless I heel-toe to keep the revs up. If I ease it down to idle-level revs then it will idle fine and not die. It still has the same bog, and lack of acceleration and overall power, and still has the P0300 code.

Does this sound like a clogged/disintegrated pre-cat, or more of a fuel issue?

Well, I thought I'd update this and see if that might trigger an idea in anyone's mind about what might be going on.

RR5

iTrader: (6)

This is an auto? Might be the A/T line pressure solenoid. I had/still have a lack of power but it got better when I went to high octane gasoline. Do you get any sounds when you give the engine revs while in park or neutral when the RPMs drop? Sounds close to a rattle. I had that, turned out it was bank 1's pre-cat. Shortly after I had to replace bank 2's pre-cat also. And I know the main catalyst under the floor is messed up and needs replacing.

dfj240

iTrader: (1)

It's a 6-Speed Manual, and I only use 93 octane gasoline in it. Previous owner only used regular though.

Without load it will rev all the way to the top, but will hesitate/bog and rattle when it gets to about 3600 and continue that behavior until about 4400 or so. Other than that, it revs fine, and will stay alive to idle after it's been revved most of the time, but will occasionally die. It seems to be able to hold it's idle better when it's cold. When it's warmed up to normal operating temperature, it struggles a lot to hold idle, and it even revs a little rougher as well.

-Nathan

Gizm0

iTrader: (1)

Check your throttle body. It doesn't seem to be the culprit, but after everything you've already done, it may be worth checking... I had hesitation/power loss/low gas mileage issues on mine after cleaning up the TB. I bought a used one from a junkyard and it fixed my problem. The electronic TB on the 5.5 Gen is very sensitive, if you moved the butterfly valve manually to clean it (or previous owner), then there is a chance it may be working improperly now...

Just my $0.02

kbcnd

iTrader: (2)

Is it possible that your VIAS isn't opening and closing properly? Do you have a BOP? I was having a similar issue where high end power was lacking as the RPMs climbed. No CEL, replaced the VIAS solenoid and issue fixed, awaiting my BOP instal though. Keep us posted.

dfj240

iTrader: (1)

I haven't messed with the Throttle Body at all to this point, which means I also haven't tested whether it was bad or not. I suppose I can go ahead and voltage test it, and make sure that it's in good order.

I checked the VIAS operation last weekend, and it was working properly. However, I did go ahead and order the NWP block off plate yesterday, and I'll be installing it as soon as it comes in.

The power loss isn't in the high end/mid/low end. It's throughout the range. It simply has no power when your foot goes down past about 40-50% throttle. If you're light with your foot then it will do just fine, and only have minor random hiccups while accelerating.

-Nathan

Gizm0

iTrader: (1)

Check the voltage from your thermistor. You said you replaced the maf sensor with a 2k1 maf, and kept the thermistor from the old maf... It may be damaged... It's a $1.50 part if it needs replacement

Gizm0

iTrader: (1)

Here is a link...

http://forums.maxima.org/5th-generat...esistance.html

EDIT: Fixed broken link

dfj240

iTrader: (1)

Wouldn't I get an intake air temp sensor code or a MAFS code if the thermistor was damaged and not transmitting proper output? I'll check the FSM to see if I can find the proper operating voltage range, and then test it anyways. Thanks for the idea mate. Always nice to have something new to check. Cheers.

-Nathan

Wow mate, thanks for the link! I think I'll give that a test immediately. Thanks again. Cheers.

-Nathan

Gizm0 - You should PM your mailing address so that I can mail some cookies mate! Just checked the IAT resistance, and I'll be darned if it wasn't 1.76k at 72 degrees. Should be up over 2k at that temperature. In complete honesty, I don't know that I ever would have checked that if you hadn't said anything.

Even if it doesn't completely solve my problem, I definitely appreciate it, cause I'd like to go ahead and fix everything I can to get this thing running perfect. I'll be ordering a replacement thermistor immediately, and I will update when I've got it in and installed, and see what she does.

I still kind of have a feeling it's the pre-cats or the fuel pump because of how pronounced the lack of acceleration is, but I am glad I found this. Thanks again mate. Cheers.

-Nathan

Amave

btw you can get a multi meter and ohm check the fuel pump.....more than likely it is not the pump because usually when a fuel pump goes bad it just stops pumping completely.


even if it was an intermittent condition it would only happen sometimes randomly .


rarely it causes a bogging problem ( but yeah it can )


i am leaning towards a sensor problem

tech44

OK, Just going to chime in really quickly here.
-Is your ECU software up to date?
-Do you have a scan tool? If so, clear your Multi Cyl. Misfire, road test it and monitor which cylinders die. Before you get the Multi cyl, you may get individual cylinders failing and setting codes; that can give you clues to where to start. You can also pull injector connectors to see which ones are causing issues.
-Did you check your injector resistance when you had the fuel rail out?
-Can you monitor your Alpha ratios?
-Check your throttle motor's spring and make sure it opens and closes freely.
-Is your engine vacuum normal?

dfj240

iTrader: (1)

Amave - I know what you mean. I've had fuel pumps fail on me before and it's usually a random cutout before they finally just give you the finger and say "Adios!" But at the same time, I did have a 240sx that had a fuel pump that simply had a peak voltage that was too low for full operation and it would cause the car to bog down and eventually "rev out" much lower than normal. So, that's a good idea, I'll check that first thing tomorrow. Thanks.

tech44 - Answers to your inquiries...

+ I do not know if the ECU's software is up to date, as I have only been in possession of this car for a couple weeks. If there is a way to check it, I'm all ears.

+ I do have a scan tool, and, as I stated earlier, I clear the malfunction codes EVERY time I finish a drive. I do this in the hopes that something besides just a P0300 pops up. So far, no luck, only P0300.

+ I have pulled the injector plugs individually while it has been acting up, and they are all behaving as they should. The resistance on all injectors is also within spec.

+ Alpha ratios? I'm a high school educated mechanic that possesses an IQ whose number barely challenges the torque output of a Honda. No, I don't think I can monitor Alpha ratios, and if I could I wouldn't know the first thing about what I'm looking at. Please explain how I might monitor an Alpha ratio.

+ Throttle spring is operating normally, and has been checked.

+ Engine vacuum is also good.

Tested the fuel pump and the throttle position sensor today. Both checked out to be good. I think it might be time to cave in and go with what my first instinct was, and buy some headers to get rid of my pre-cats, which I believe to be clogged, or at least clogging. So that's next, and if that doesn't work, I'm about fresh out of ideas.

-Nathan

tech44

alpha ratios you can monitor in your data stream with a scan tool; well I know you can with a Consult II.

Have you checked your exhaust back pressure?

When the Consult II prints the DTC results, the part number of the software is on the top of it.

dfj240

iTrader: (1)

If I had Consult II, I probably wouldn't have even had to start this thread. I do not have the ability to measure all of these crazy sophisticated values. I have simple tools, and simple diagnostic scanning equipment. I don't work at a Nissan dealer, I just have a simple mechanic shop. If you have something for me to actually check, please let me know, and I'll check it. But you keep wanting me to look at things that not many people have the ability to look at, and you clearly haven't read through the original posts in this thread, otherwise you wouldn't have asked half the questions you asked in your first post. I know the almighty power of the Consult II, and I will take it to my local dealer, who is worthy of harnessing such a power, if I can't get it sorted out myself.

Now, if you have something helpful for me to check with a Cornwell Portable OBDII Scan Tool, or a multimeter, I'm listening. But, I have already checked quite a few things, so, if you would, please read through the rest of this thread before chiming in again. Thanks mate. Cheers.

-Nathan

sontakke

Can you watch MAF readings live? Assuming you have the factory service manual, even if the results are in the spec, you want to make sure it is on the higher end of the scale. Take readings at idle, part throttle and WOT.

I definitely remember when I had trouble with MAF, it still met the specification listed in the FSM but it was at the lower end of the scale. When I put the new MAF, the numbers jump considerably along with the power. I understand you have already swapped MAF but who knows, you might have got a bum one.

dfj240

iTrader: (1)

If I had the Consult monitor, I could, but the best I can do presently is monitor voltage and resistance. My old wasn't "bad" per se, but it was, as you describe, at the lower end of the scale, which is why I changed it. So I know exactly what you mean.

I did check this new one, and it checks out to be in excellent working order. The only thing that was out of spec was the intake air temperature thermistor was not up to spec. I've ordered a new one already, and should receive it in the next few days.

I was really hoping the MAFS change would sort out my issue, and when the MAF tested poorly, I was quite hopeful I had nailed it. Then I became sad. And here I am now. Lol.

-Nathan

simpleNclean

i just rebuilt my motor and when i went to crank her she would idle rough and would bog when reving and shut of.....to come and find out my high *** put the maf housing the wrong way.....i turned it around and it fired right up and revved beautiful.....my 2 cents

MrEous

iTrader: (11)

Hey Nate...

I have Cipher and it can do data-logging if you need to do some of that. I'm not sure of all the variables it can log but if you find it will help you then you can borrow it.

Lemme know!

(Jeff)

dfj240

iTrader: (1)

That would be killer Jeff. I'll research what it can log and see if it will help me. If it can, I'd be more than appreciative to borrow it to sort this out. One way or another, when the Maxima is mended and running properly, I'm going to bring it your way and let you check it out. I'll probably make it out to one of the DFW Nissan meets or something.

-Nathan

Alright, forget all this explaining through text message. If any of you are anything at all like me, a video would be much, MUCH better than a bunch of random, potentially confusing text. Therefore, I'm going to hook everything back up that's currently disconnected, grab the camera, and go for a quick drive, and bring back a nice video for you all to watch. Stay tuned!

-Nathan

A video of exactly what I'm experiencing. Hopefully this can help someone help me sort this out!



And after that drive, I took my idle running data from my OBDII Scanner. I took pictures of the screen, but they were all blurry, as the camera couldn't focus, so here they all are in list form:

MIL Status Off
ABSLT TPS (%) 0.8
ENG SPEED (RPM) 600-628
CALC LOAD (%) 17.6
MAF (LB/M) 0.37
COOLANT (*F) 203
IAT (*F) 109
IGN ADV (*) 13.0-16.0
ST FTRM1 (%) 5.5
LT FTRM1 (%) 9.4
ST FTRM2 (%) 21.9
LT FTRM2 (%) 9.4
VEH SPEED (MPH) 0
FUEL SYS 1 CLSD
FUEL SYS 2 CLSD
O2S11 (V) 0.060
ST FTRM11 (%) 6.3
O2S12 (V) 0.030
O2S21 (V) 0.010
ST FTRM21 (%) 21.1
O2S22 (V) 0.020
MIL DIST (mi) 0

If anything jumps out at anybody, you have my undivided attention! I'd like to get this thing sorted out as soon as possible. Thanks.

-Nathan

Gizm0

iTrader: (1)

When you rev it in neutral with your foot all the way down, does it take long for it to get up to the red line?

dfj240

iTrader: (1)

Nope, it will rev fine, but it will stutter randomly throughout the range starting at about 3600-3800 rpms, but not for more than a few hundred rpms.

My main area of question is bank 2's short term fuel trim, and why it is 4 times higher than bank 1's... What would cause this? Should I be looking possibly at an o2 sensor possibly giving a false condition causing the ECU to think that bank 2 needs more fuel than it does?

I monitored both banks fuel trim just under a short, quick rev to about 2400 rpms and bank 1's fuel trim didn't ever go higher than about 7, and went as low as -3 or -4, but bank 2 went as high as 23, and never went lower than 19. Could that be a product of a clogged pre-cat, or is it likely to just be an inaccurate o2 sensor, or something else?

Thanks for the help. Cheers.

-Nathan