First Code was P0100

Second Code was P0325

Car goes into Limp Mode after a few minutes of driving, turning car on/off is a temporary fix for like 2 minutes and it happens again.

I replaced the MAF Sensor from a junkyard for like $24 and it still occurs. I can't make it to an auto parts store to have it tested and I don't have a OBDII scanner myself. As of right now I got a flat tire on the car I used to go to the junkyard and that's at the shop. So now I have no car to go any where except for this..

I ordered a Knock Sensor anyway for the second code and I can't tell if I got rid of the first code because the previous owner or whoever checked the ECU to do diagnostics, made it to where I have no screw to look at in the hole...can't even feel for one.

Can anyone help because this is my DD and my job requires my vehicle?

Thanks

 

P0325 is your knock sensor. If not functioning properly will cause the car to use retard timing (limp mode). Change the sensor and see if that helps. It's located on the top of the block under the Lower intake manifold. It's sorta a pain to replace without removing the manifold but isn't impossible.

 

Do you have a multimeter? Use it to check if your MAF sensor and wiring harness are both working properly. If you don't know how to check go to:

http://www.nicoclub.com/FSM/maxima/1997/EC.pdf
(look on the left where bookmarks are and scroll down until you see "DTC P0100, Mass Airflow Sensor (MAFS)

or

http://easyautodiagnostics.com/nissa...n_maxima_1.php

 

MAF will cause different symptoms. If the car runs fine for a few min, you can rule out the MAF. The knock sensor seems to be the problem. If you want to test it you can try doing the knock sensor resistor mod. It's here on the org. Just search for it.

 

The knock sensor will not cause limp mode, most would never feel any effects of a bad ks.
Check the MAF sensor, it's electrical connection and wiring to it.

 

edit: found!

http://forums.maxima.org/4th-generat...tall-pics.html

 

I agree. I have a P0325 and my car runs fine. I'm with njmax and suggest you check your MAF and its electric harness.

 

ask shockandawe he knows all about limp mode.

 

most wont feel affects from bad.knock sensor?? i personally beg to differ... i had a bad knock sensor, your going to see a big difference ib gas mileage for starters, for two once i changed mine i could feel the difference... not like goin from 200-300 whp but.it.is.noticeable... its a 20 dollar part and takes an hour.tops to change without removing manifolds and.all that.. you just need small hands...

 

lol go check the thread you speak of. It is a fact just took awhile for others to realize they were wrong.

 

So i basically went to work with a different car with problems and am trying to decide what to do.
So far i changed the MAF sensor and still goes into limp mode and i am waiting for the knock sensor with harness to come in. When i get home i will test the maf harness. If that's the problem will i have to order that online as well?

 

If im not mistaken the maf harness is part of the FULL engine harness,pending where its broken you can cut and splice,OR pull a full engine harness from a junkyard car but thats time consuming between two cars removing aned installing....

 

Whew, knock sensor resistor mod solved my problem, at least until I can get the time to replace the knock sensor + harness..

 

Bam, called it from the first reply.

 

Hate to break it to you but fixing the knock sensor had nothing to do with it.

Cam, crank, and maf sensors are all things that will cause a fail safe mode (There are several fail safe modes as well), bad ecm as well (Rare occurrence, I only mention it because of your stripped screw). Infinmax, you also said 'car running fine for a few minutes can rule out maf', maybe in closed loop but during open loop conditions car won't run without maf.

 

Perhaps while you were working, moving things around your poor connection to another sensor was wiggled tight?

A knock sensor will not put a vehicle in limp mode, and as I've said before, most wouldn't even know its dead until they pulled the code.

 

haha of course my car was running fine all last night and now on my way to work the problem reoccurs. i tried cleaning the maf sensor and the harness, then replaced it altogether, then did resistor mod, and even replaced the ECTS as i have read on one thread and now i have no CEL but it is still reoccuring.

edit: one thing different i noticed is when i turned the car off my car and turned it back on, the rpms stayed at 2k idling for a few minutes then dropped below 1k idling, if that helps any..

 

You have to describe what u mean by "limp mode".

If u are referring to the A/F parameters that the car will default to if the KS is bad, then yes u are in limp/safe mode. A bad KS will not cause driveablity issues.

If u are referring to engine buckling, hesitation, sputtering, shutting off...then you are in limp mode as well. But u will barely be able to drive the car or rev past 2500 rpm. These are all classic MAF issues.

You issue is with the MAF. The one u got from the junkyard is faulty. Autozone got good MAFs or try here on the org.

 

that is what i wanted to avoid paying. im guessing i still should test the maf harness and make sure that isnt the problem either

 

Checked this when I got home, and I'm not getting any reading on the Red or White wire when tested when diagnosed by the 2nd link.

So this means I have to scour the junkyard for this?

 

So it's your MAF electric harness huh? You could get it from the junkyard but make sure it works. You could also go to the dealership... thing is dealerships always overcharge

 

I'm just afraid to unwrap all the electrical tape and expose all the wires and fry my brain instead


edit: I just have a feeling that maybe I'm not testing the wires right although I followed the guide...and before I tackle that issue I want to get my brother to do it for me since he's an electrician



Also, I know this is a long shot but could this filter be causing the problems?

http://www.autozone.com/autozone/acc...er=628426_0_0_

I have this connected to the MAF using this mod:

http://www.vqpower.com/v2/articles.php?article_id=47

 

4g mafs are pretty bulletproof, very very rarely fail. I've dropped them, kicked them, cut the ends off with sawzalls, sprayed them with everything from water, non-chlorinated brake cleaner, boost, oil, and nitrous oxide..... & I've yet to kill one, though I have seen at least once one that misread a little bit & caused poor fuel trims & mild stuttering/misfire.

Double check for 12v at the red wire with key on again. You can disconnect the harness from the maf & check directly from the maf harness terminal to battery -, to avoid newbie backprobe errors. If no 12v on that red wire check fuses # 57 (7.5 AMP) & #60 (10 amp). If 12v present clean & retighten sensor grounds on intake manifold (You should do that anyways) & recheck the ground & signal circuits. If 12v not present & fuses good we will move onto the eccs relay part of the circuit which I doubt would give a problem.