Today, Installed new High flow cat and full catback. finished the install. Started it. no leaks. Time to rev. it wont let me go over 2400 rpm. I warm it up. Drove it and will not go over 2400 rpm. checked all my o2's. they are fine. my maf is plugged in. I dont know what to do, I have work 9am tomorrow morning. oh dear. Help me with ideas on what it could be.

 

wow that really sounds crazy, never heard of anything like that man, hope you figure it out....

 

could be the MAF crapped out or the TPS crapped out here's a thread that may have some suggestions http://forums.maxima.org/5th-generat...=ecu+limp+mode

If you have a can of CRC MAF cleaner try giving it a good cleaning and then try the engine restart again and ref. http://forums.maxima.org/5th-generat...ht=MAF+cleaner

 

Did you get it figured out?

 

Any codes? Sounds like the TPS.

 

Sounds like MAF to me.

TPS will usually give you a flat spot, but if you pump or feather the throttle you'll get past it.

Was the MAF disconnected when you did the install?

Maybe reset the ECU before you rush and look for problems.

Since the car is breathing better maybe it thinks there is some sort of problem with the exhaust and it is in some sort of limp mode.

 

I did the ecu reswap as well as Ahmad_1290. Since mu_03sp isn't here to answer these questions, I was there and i'll reply to try to get him some answers asap.
Maf was on during instal, wasn't disconnected. The ecu reflash we already tried. If you downshift you CAN get past 2400 rpm but you can floor it after and it won't move PERIOD. limp mode? idk..

 

is it a 6sp? If so, the RPM you can downshift to means nothing since the ECU has no say in your downshift. I would suspect that in an auto, limp mode would still let you downshift to over 2500. I assume by saying that you did the ECU switch you mean you did the pedal procedure to reset the ECU?

Check ALL the wiring connections on the engine that you can find, even if you didnt mess with them.

 

Sounds like a bad MAF man... hit up DaveB... try cleaning the MAf also...

 

maf sensor is gone or the TPS do u have any codes scan it what u need to do is unplug the maf sensor and and rev it see if anything change also do the same for the TPS sensor hit me back

 

It was same with or w.o the maf plugged, so assuming that's a maf problem. Also it is a 6mt, the pedal procedure was done. ocne you downshift though, lets say u go to 4k, you can punch it and get no where. Everyone pointing to a bad maf, could it just go bad over night like that? Or is the ecu just confused? not tuned btw.

 

reset the ECU then, if its a problem like explain the car will immediately do the samething... same with my sputtering problem, i reset the ECU and with the CEL being off for a couple of mins the car still acted the same... check for the APPS (accelerator pedal position sensor) code also... IIRC it will cause that problem i forgot the code number IIRC its P2138... i had it with mines also (it just stopped fo some reason)

 

As soon as mu makes his **** back to this thread, we can all go from there hahha

 

Happened to me once, it was MAF going bad.

 

i'd assume it's maf. But never heard of it going bad suddenly.

 

whats the code readings???

 

how many miles? also, mafs dont "go bad" they just stop working. the maf operates off of a thin, delicate wire. so its totally possible for one to $hit out overnight.
when i first installed my injen cai, the same thing happened to me. i got done with the whole install process, tried to get on it, and *chooooooke*. turned out to be the last thing i expected, the maf. so check it.

highly doubt its the tps.

 

It's more than likely maf, I think you all can call this closed.

 

e-subliminal-2: Its not Maf. I cleaned it and did no difference and i have 130k. i have a feeling its my o2's. i extended 2 of them for my headers. so i was told i am having a shorted wire. so im gonna try to get that done soon.

 

e-subliminal-2 Give me your maf haha. let me see if my car acts different.

 

let us know what happens

 

if you have 130k on an original maf then its probably it try swapping maf's with someone elses maxima

 

if you have shorted 02's you wont be in limp mode. you can check to see if theyre shorted because the fuse under the dash will be blown, but either way you wont be in limp mode.

 

Seems like MAF for sure. Clean it and see if that helps

 

MAF sensor. Time for a new one.

 

It will not be the o2s... MAF for sure.

 

He already did clean it

And dude its your MAF I know you want to deny it but it is.

 

IDK if it will work for you but what I do is drive, once it bounces one time, I stop, shut the car off and then restart and drive again and works fine. The only electrical change I made was disconnected my EGR but i have a 3.0.


Let me know if that makes a difference.

 

mine was having the same symptoms and it was the MAF, got a new one at advanced auto parts for 100 bucks or so.

 

it probebly will be... i was talking to him over the phone and he explained the problem... he was having the exact same problem i was having... nobody here helped me out nor had the solution, it was that one or more bank was running extremely lean because the contact from the extended o2 sensor wire and the wire he uses for extention doesnt have enough contact on it, causing the car to bog and at a certain RPM kicks like you have NOS and acts normal (even causing the p0300 code like i had also)

 

Your car is in Limp Mode, my friend, which is virtually a "safe mode." It minimizes speed and RPMs in an effort to protect the engine from damage. (If you're familiar with Windows, its like booting your computer up in Safe Mode.)


Mine did the same thing on several occasions. ALL of the dash warning lights lights were on (Slip, Traction, SEL, Transmission, battery, oil, etc) and the car threw about 12 different codes.

In my case, it was the TPS.

 

lemme see if i can help u guys a lil bit... after 4K rpms his car kicks out of limp mode and acts fine... not a TPS, car not going over 2.4K will most likely be though... can also throw the APPS code, but if it acts fine over certain rpm other problems may be a factor

 

I don't feel like having mine blow up under your car

 

Cleaning an already dead maf btw won't change anything. Once it's gone it's gone. You can clean it to TRY to prevent it from going bad if you feel it's weak, but once it's dead you're just beating a dead horse.

I'm still shooting for maf. I'm not too familiar with side effects of a bad o2 though, so w.e it is. gl.

 

I had cross-wired extensions on my rear main O2 when I installed my headers that was resulting in the fuse blowing. However, while it was like that I was still plenty able to get above 2400 rpm and the car was still just about as fast. If the fuse is blown, then it doesnt matter anymore what the O2 is doing since the ECU cant use the 02 signal. is he having the same "dead spot" problem you were having? If youre WOT, it also doesnt matter what the O2 is doing or even if the fuse is blown since the ECU ignores O2 input

 

a bad O2 wont cause you to not be able to get over 2400 at WOT. At WOT, the ECU does not use O2 input, so your O2 could be relaying any condition, crosswired, blowing fuses, w/e, the ECU doesnt care because the O2 signal is being ignored

 

what i was posting was not an opinion it was a fact... i never said he had his o2 wires mixed up... basically the wires dont have much contact so while he is driving regular (when the ECU reads from the o2 it will bog, at WOT it wont) i agree, hence why i try to clarify his post based on a phone convo me n him had... it struggles to go past 2.4K but after 4K it will kick and act normal because at that point the ECU isnt reading from the o2 sensors... i literally just got done with this problem less than a week ago thats why im posting this... unfortunately it cost me a Maf cleaner $100 in spark plugs wasted time and $77 at the mechanic just to find out when we untaped the connected wires it barely had any contact, just tryna save him from the same thing would it hurt if he just rechecked his wiring??? whats the worst that could come from that???

 

i agree he should check his wiring. I was just clarifying the WOT thing. The op never posted that he could get over that barrier at WOT, which would have been pretty vital info. if he CAN (which you say he can) then he does not have an MAF problem

 

failure to get over 2.4K rpm is not a 100% maf thing depending on what the CEL code is, it could be an accelerator pedal position sensor (P2138), at WOT the car will go at a max speed of 25mph and wont exceed 2.5K rpms... not his problems however but im just stating this to let others know before jumping to a conclusion about a car staying at a certain rpm that it can be other problems also

 

The most common problem for that though is a maf. As I suspected from the geko, It was a bad maf. Mu was just over, we swapped mafs and his car ran like a champ (obx headers btw did make a noticable difference in the rpm and speed range, speaking from the difference of mine). It was his MAF thread closeddd