cleaned TB + relearn + success + failure?

[fitness stain]

i've had minor issues out the a** for the past few months. 2002 SE 6MT. Approximately 115k on it.

i blew a MAF ... finally got a working MAF and all was good, except that once the car was warm it would sometimes idle low and start to stumble ... eventually it would stumble so low it would die. Usually at red lights or while coming to a quick stop (braking, then clutch quickly).

Car would start back up always and idle for a time before repeating the stumble process. Car idles a little low ~5-600RPM on average.

Reading through other forums led me to clean my TB the correct way with the car in gear, key in the ON position and pedal floored to open the butterfly valve in the TB. It was dirty as hell in there so i soaked it with TB cleaner and wiped out with a clean cloth. it wasnt spotless when i was done, but a lot of the gunk was cleaned out.

When i started it up sure enough i had the high idle. It would rev to almost 2k when you first turned it on, eventually settling around 1100RPM. When driving at low speeds it was really jerky and the car would drive itself since the idle speed was so high (1500RPM) .. when i came to a stop or pushed in the clutch it would surge to around 1.5K then settle around 1100RPM.

So i've done the 4 separate pedal dance procedures ... finally just recently i completed the idle air control reset to good results (after doing all the other dances as a prerequisite) . I completed the process, started the car and let it idle for 20 seconds .. and after revving a few times the idle fell below 1100 which is where its been since i cleaned the TB. It eventually settled at just where it should be 6-750RPM) ... i was stoked. turned the car off and had to leave it there for about an hour. Started it back up and the idle stayed where it should have been.

The issue is that now its back to idling low and stalling eventually. With a vaccum leak wouldnt it idle high? What else would cause the car to idle a little low and eventually stall? It only starts to stumble and sometimes stall once its been sitting idle for longer than 10 to 20 seconds ... I assume the ECU has some routine it goes through or some part that causes the idle to lower a bit once its been idling for longer than 5-10 seconds? same pattern every time. Idle is great upon first stopping, then after 5-10 seconds it starts to lower down to around 500RPM .. sometimes if i dont give it gas it will just eventually stall completely.

I know the IACV "function" is working cause if i turn on the A/C the idle bumps up some, so that feature is working (regardless of whether we have an IACV on a 5.5 or not, the process of raising the idle based on accessories turning on works)

So i'm not sure what else to try. The CEL was on when i started it after the successful test, and i havent reset the ECU yet since that CEL has come on. I pulled the code and its the P0507 high idle code. i wanted to ride around for a little while to see if it cleared itself. Figured if the car was still learning new parameters (causing the idle to not be perfect and stall), by the time the code cleared itself the idle should be completely learned (that's my thinking anyway)

Would this dying just be the car still trying to learn the idle, or should i be suspecting something else?

I do have oil in my rear bank driver side cylinder. I changed out the spark plugs about a month or so ago and that was the only cylinder that was leaking. I plan on buying an 04 rear VC and the appropriate gaskets in the next week or two, but surely that alone wouldn't cause this? I assume that's just my main reason for burning oil (something many of us 5.5 gen'rs are aware of)

Thanks for any help anyone can provide.

[loystock]

Welcome to NICO.

I cleaned up your posting since we don't allow links to competing sites. So please be forewarned.

Unfortunately, the recommendation you got from the other site will cost you a lot of money. If I'm not mistaken, the 02 Maxima has a a Drive-By-Wire Throttle and as such, no cleaning of the TB is recommended by Nissan. This type of throttle assembly has very sensitive components that can easily get damaged during cleaning. Please note that the the throttle valve plate has an anti-gunk coating which may appear to be dirt. If you remove that, you will have a high idle problem. But the fact that you soaked the assembly with cleaner just made it worse and probably damaged the TB sensors beyond repair. You have to replace the Throttle Body (@ $400) then have the ECU reprogrammed ($60-100). It's also possible that your ECU got toasted when the TB failed. I hope it's only the TB that failed and not the ECU. Otherwise, more money down the drain.

[fitness stain]

I actually resolved this just the other day.
instead of blowing ~500 for a brand new AM600 MAF, i got a junk yard unit for testing purposes ... installed it, cleared the ECU using the pedal dance/ignition method and car has been perfect sense.

While it is very possible to screw up the TB by cleaning it, if you follow the proper procedures its possible without any issues. I'm an example of that.

Thanks for the advice though, and sorry about the links.