I recently did a bunch of work on my 03 maxima. Removed upper/lower intakes, replaced plugs, installed NWP spacers and gaskets, cleaned throttle body, installed a getto oil catch can, and installed a short ram intake. I performed all 3 of the relearn procedures as needed just like the NWP instructions say. All was good for about 2 weeks, ran awesome no problems, then I got a P0507 code (high idle detected) after starting it up at the gas station. I did the ECU relearn and Idle relearn, no prob, CEL dissappered. No problems for another 2 weeks and now the P0507 CEL is back. I have checked the intake and the NWP spacers/gaskets for vacuum leaks and everything is good. I can perform the Idle relearn procedure and the idle drops back to where it should be 725-750 RPM, but after a few restarts the idle creeps higher and eventually triggers the P0507 CEL again! Is there something I may be missing here? Could it be a bad MAF? Could it be my getto oil catch can?

 

So when I did my spacers originally, I ran into this problem. When I was handling the throttle body, I accidently moved the butterfly. I had the high idle problem, and even with the relearn, but would go back to high on the next restart. I ended up replacing the throttle body and it resolved my issue.

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I was afraid that would be the solution! I even took precautions before I cleaned the TB,( ignition on, pedal pushed). I guess you shouldn't even attempt to clean the TB on these cars! I just don't understand why it takes the relearn then a week or two later it throws a code.

 

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Buy that kit thing from NWP

 

Yea im deffintaly understanding why people fu.. with u George.

Before u did the idle did you do the accelerator release position learning and throttle valve closed position learning? Worth a try. Those 2 supposedly are to be done before idle learning or it won't work. Make sure steering is straight and all switches are off engine is hot sunroof closed.

Exactly how did u clean the throttle body? Did you let it dry? Some people had success doing it u must of moved the plate with the ignition off. Im curious to whats causing this since u said u had the throttle open with switch on.

 

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I have a 2002 throttle body working for sale !

 

Thanks for the input everyone! Yes I did all 3 relearns and also a ECU relearn. I cleaned the TB with it detached from the intake but still plugged into the wiring harness, with ignition on and pedal pressed to the floor. The Idle learn procedure works great and resets my idle to the correct 725-750 range. But after as many as 10-15 restarts or a week or two, the code comes back. Maybe my TB is toasted and I moved the plate at some point during the work. Looks like a new TB is going for about $200, not bad, I thought they would be a lot more.I'm going to try a few more things before I bite the bullet and get a new TB.

 

UPDATE: I finally went ahead and bought a new throttle body (Hitachi, $217), and installed it this weekend hoping to put an end to my CEL issues. No such luck! Same exact symptoms as before, takes all the relearn procedures no problem, (ECU relearn, accelerator release, throttle body closed, and Idle relearn) and resets my idle to 725 when in gear. But after a couple restarts its 800, then after a few more its 850, then eventually triggers a CEL. I'm starting to think now that its my ghetto oil catch can setup or something to do with my SRI, maybe even MAF? The battle continues!

 

I had experienced this situation. I guess some cars can do the relearn procedures but mine couldn't. I spoken to NWP and they suggested to unplug the batter for over 24hrs so all power is completely drained but no result. I finally took it to the dealer and $120 later with my airbag recall fixed it was back to normal.

 

UPDATE #2: Problem Fixed! Finally after about a two months of battling this issue on and off, I think the gremlin has gone away. I really did not want to take the Max to the dealership for a ECU reflash and relearn, so as a last ditch effort I disconnected the positive battery lead and let it set for about 3 days. After reconnecting the battery and starting the car up, the idle was perfect (700 rpms)!!! I went ahead and did all the relearns anyways and after a few days of driving and a lot of restarts, the idle is still at 700. I know the battery disconnect method doesn't work for some, but it solved my issues for now.




I wanted to share my success story so maybe it would help out someone else who is on the brink of taking their Max to the stealership for a high idle problem, and thanks again to the Org for all the input and endless info available on this site!