Maybe a knock sensor gone bad, pulling timing and adding fuel. It would be more noticable after warm up.

 

What you need to do is look deeper than just the stored/pending codes. Find a shop that can view the "data stream" while driving the car.

They'll plug in a hand held machine to read the output of every sensor in real time while driving the car. They can do while the car is cold then hot. A good mechanic will be able to interprit the readings and tell you what's going on. At that point you can have them fix it or pay for the diagnosis and fix it your self.

The trick is finding someone who can look at the stream and actually know what's going on. A lot of shops, including dealerships, don't have someone who can do that. You might have to call around to some import shops and talk to them about it.

 

did you put the stock airbox back in?

 

I thought smart people like that only exist in movies like Fast & the Furious, but seriously though I have no idea how to look for a place that does that kind of stuff even in a business crowded Orange County, CA

 

I threw it away a long time ago when I didn't even know that I could at lest sell it on this forum

 

I may be trying the stock airbox, but I don't know how the "cold air" intake would make the car lose performance.....

 

the fact is that it's not sucking cold air once the car has warmed up. when the air gets passed throught the radiator, it gets hot. and hot air has less density.
the stock airbox on the other hand, sucks air before the radiator, so the air is cold.
car manufatures are not stupid.

 

go to a junk yard, I bet you can get one for very cheap.

 

lol not stupid...theory makes sense ill test it out today

 

I took my car to Technosquare in Torrance, CA a couple months ago and he fully inspected the CAI in regards to the issue, re-programmed the ECU to conform to what the CAI was doing and reported that the CAI has nothing to do with the problem and it is not causing the issue. The only problem is that he is so BUSY he wanted the car for >2 weeks to figure out the problem and I couldn't give up my car for that long.

Additionally, I owned my CAI for a year with no problems before this issue even came about so I doubt the car would have no probs for an entire year and suddenly go numb.

 

^ cool, well you tried stuff to no avail, our issues may be the same or slightly different..so despite what he says im going to at least give it a quick whirl

 

Yes, that would make perfect sense if it weren't for the fact that my CAI delivered breath-taking performance for an entire year and it was in the same exact spot.

 

Yeah, you're right, most people here probably just have similar loss of power/acceleration for who knows what other reason.
It might be that the only reason we have the cold power in common is just because the ECU tries to warm up the car as quickly as possible and so over-rides all sensors & stuff telling it to slow the F down but as soon as the car warms up the ECU goes into *****y mode and functions correctly by telling my car to slow the F down because there's something not right.

 

I previously mentioned that since this issue came up the noise coming from my CAI has decreased from a fighter-jet like noise to a wussy like noise.
Could it be that my throttle body has gone bad again but not bad enough to throw a code and is not opening enough to allow the engine to breathe.

What are your guys thoughts on replacing the throttle body to possibly fix this?

 

Is the filter on your cai dirty?

 

I would try to take it to another shop, and ask what they think. I'm going to try a couple more things and see what happens but not just replace tons of parts in a guessing frenzy.

 

Once the dirt on the filter warms up it must make the cars performance go bad....there change our filters

 

if the throttle body is acting, it'll be the same whether it's cold or warm.

 

Have you ruled out vacuum leaks? "Warmed up" is still pretty vague....do you mean after the coolant has warmed up or after the fuel system is in closed loop, O2s giving data, etc...

 

For me, its pretty much once the temp gets above the first to second mark on the gauge. Then she doesnt perform as well.

 

Have you tried getting your gas from a different place? Engines are more prone to knock at higher temps and less likely when cold. A knock sensor that is functioning perfectly will alert the ecu of even the slightest hint and the ECU will pull timing. I don't know for sure, but since the vq35's throttle body is electronic and controlled by the ecu as well, maybe it closes the throttle some too?

For 35 bucks my friend got an OBD2 elm 327 reader off of ebay and he gave it to me (hes getting VAG com for his GTI which can do a whole lot more), and when plugged into my laptop I can read and datalog my throttle position, airflow, ignition timing, vacuum pressure and a whole bunch of other stuff.

And that is on the retarded 1997 4th gen ECU too. The 5.5 gen ecu should be able to output A LOT more data. Then you will be able to figure out if the ECU is pulling timing, closing the throttle, etc.

 

Yes it is dirty and greasy looking, I have a bad-*** AMSOIL oil-free filter on order. (Better than K&N)

http://www.amsoil.com/StoreFront/eaa.aspx


How hard is it to change the air filter myself it seems really hard to get to down there? (INJEN setup)

 

I've gotten gas from many different places around my area. I try to stay at one location but it never works out.

Just take the tube off past the MAF and then replace the filter, then put the tube back...fairly simple.

 

well it sounds like you're know what you're doing but I wouldn't know how to interpret the data anyways.

 

I always get it from COSTCO or Mobil 1 but many different locations all the time so I doubt that COSTCO & MOBIL 1 both suck, plus I only get 91.

 

$tealer$hip and Technosquare have both told me " it looks like there are no air/vacuum leaks "

 

Could this lack of power be the alternator?

I say this because before the Maxima I had another friend called the Altima and the alternator went bad on it and I got a rebuilt one and the car was running well but very lack of acceleration power. This was very obvious because the lack of acceleration power came JUST after alternator change so they changed it again and I got the power back...

I read somewhere that modern alternators especially on a bad-*** car like the Maxima have more complex technology that have the ability to run even though their slowly dying inside.
...and perhaps thats why my car is running so smooth and I'm getting 30.4MPG because the alternator is alive and well to deliver enough power for grandma to drive but not 100% all there to " GO TO WORK " and give an EXPLOSIVE performance like it used to under HARD acceleration. Maybe when we floor it that's when the engine demands a little more electric power from the alternator than just the regular flow from the battery combo and so the alternator can't deliver and so no explosive power?
...and maybe since the alternator is so tired out it gets worse once it heats up so that's why it won't generate as powerfully anymore?

..and of course the charging system passes all diagnostics that AutoZone or stealership would do because it can't be tested " UNDER LOAD " unless it is taken out and that's when the problem exists...and if I'm going to spend the $ to take it out might as well replace it.

Any ideas? Thanks.

 

Sorry for addressing so much info but I wanted to focus attention on the fact that I'm getting 30.4MPG highway and 24MPG street which is amazing but lack of power on HARD acceleration, how weird is that? anyone else have this weirdness? that's why I'm thinking about the alternator being a problem just not being up to task on hard acceleration?

 

If you're basing your mpg figures on the trip computer then you might be surprised to know that it is usually off by about 4-5 mpg. So you're probably getting 20 city and 26 highway which is the EPA estimate for this car.

 

Yeah it sounds like we are having the same issue. From a stop to a hard acceleration while cold it runs great 0-80. Then after that if I try again it runs slower...very noticeable. The 60-80 kick down (auto) is great when its colder. However when it's over 2 ticks on the temp gauge, it sounds like it's working hard, but not going as fast as it should. I get about 345 to the tank under normal spirited driving both freeway and city.

 

im getting the same sorta lack of power, friend sez its the alternator and hes a pretty good engineer and solved plenty of my other car problems... but honestly hes not a mechanic, so im not gonna act on his judgement call but it would make sense...

if anyone with lack of power changes out there alternator and/or fuel filter and regains there performance, be a good samaritan and let us know here on the forums. im sure plenty of us want to know.

 

Not that I'm going to try this because it is a little expensive of a part to just " try out " but out of curiosity is changing the alternator something we could to ourselves? any good instructions out there? or is this just too hard without proper levereage and/or special odd tools? (raising car, etc..)

UPDATE:
From this link it seems too hard and part is still too expensive just to try out:
http://forums.maxima.org/5th-generat...-write-up.html

I'd much rather replace ~$20 parts to mess around, anyone know what the following thing is, I have no idea but it looks like i'd be fun to replace!

 

I have this same problem on my 2000 se. I hate it with a passion.



Ive changed the alternator on an rx7. You just need some sockets and *****. ;-)

 

I'd much rather replace inexpensive parts for fun and then see how my car functions afterwards.

My latest target is this object pictured in the link below.
I have no idea what it is but I have a strong desire to replace it!



Anyone know what that is?

I am PRETTY 1% SURE that after I replace it my Maxima will go fast again!

 

That's just a vacuum canister to open the VAIC. As long as it holds a vacuum it's OK.

As far as finding someone to read the data stream, those people are out there. You should be able to find one near you. I sell cars through a shop who specializes in that sort of thing. Shops from all around the area send cars to us when they're stumped. If you call a few shops you'll either find one or they'll recomend one.

In the time you're taking to guess what part to replace next you could find someone to do it properly and for a lot less money.

 

I'm having the same issue, but a bit more serious. Keep getting p0011 and p0021 codes. No power over 2,500. Worked the entire flowchart which included replacing the intake with the stock intake and MAF. I did this even though I had tossed my original factory intake years ago I Called LKQ, nationwide junkyard and they had it. MAF and entire factory intake assembly was $95. This *DID NOT* fix my problem. I have changed all sesors, new O2's, MAF, Cam, Crank, ECU. Still no power on hard accel and keep getting my codes.

There is a TSB for low oil pressure. Monday when I'm back at the shop I'll test that and repost. I was racing the car real hard when this problem started and threw the car into limp mode. It has not run well in over 4 months because we are stumped at this. I have pulled my harness out and tested continuity and checked all grounds. The engine is spotless inside and out. Swirl valve works ok too.

 

forgot to do my stock box, but i did notice how f-ing hot the intake gets.....and felt the hot hair blowing directly onto the filter and pipe.....

 

Someone already told you, knock sensor. Search for the resistance value and go to radio shack and buy a pack. Just unplug the connector for the KS and fold up the resistor leads to make good contact and tape it in there. Problem should be solved.

I know b/c I had the same problem. Let me guess, it runs a little better if it's cold outside even if the engine is warmed up? If it's hot outside the car will barely run and backfire out the intake.

BTW, after running that rich for so long, I bet the plugs are crazy fouled. You might as well replace those while you're at it.

 

I might have an idea. It is out there, but it is an idea.

1.) How miles on your max?
2.) Does it consume any oil?

From what I hear VQ35's tend to burn oil like a 60's chevy once they get to about 100K. If yours is using up more than a quart of oil between oil changes (hopefully it is not, but I have heard of it happening on the vq35), it could be possible for that to damage or clog the cats. I have heard of oil burning being bad for the cats, and a plugged up cat might cause this. As someone mentioned earlier in the thread, they had this happen and it affected their performance more when it was hot.

Probably not the case, but just a theory........

 

Your advice actually gave me more of a headache than my local stealership who told me there's nothing wrong with my car simply because there's no check engine light and it starts and moves.
I appreciate your input but unfortunately we're not Master Nissan Techs here so we have no idea what you're talking about,

* "Knock Sensor"? What the? Where is it?
* "Unplug connector for the KS"? What the heck is KS?
* Fold up resistor leads? Uhhh?
* "Tape" I know I'm not technically "aware" enough but taping stuff doesn't sound right...