Ok title says it all, installed those 3, had the locksmith sync my keys. Drove for a while and popped that code again. Here are my possible causes. Please add to the list and comment on those you think are likely or not.

ECM was bad already
Bad IACV (twice)
Bad wiring (iacv plug or ECM plug or somewhere in between)

I just want Maxine running right and those 5 mpgs back

Good news is I now have a second ECM on hand to send for repair. Both the IACVs were OEM and sourced from Courtesy parts in TX there.

Edit: I should also add that an idle relearn has not been done, but I don't think that should cause it to throw the code should it? Just idle out of normal position.

 

Maybe some info on what was happening before? I was just about to post about my experience with the idle relearn and will post here, maybe can get some help regarding both out issues.
So I was experiencing sudden drop in revs around town when stopped at lights. This was happening pretty rarely but concerning nonetheless. Well took it to a mechanic and hes like TB needs cleaning and after some research I thought yea its never been done in my possesion (almost 4 years now) so not a bad idea. Well from what I saw online vs what he did caused a little concern to me but I left it to him since hes the expert. What he did was sprayed some sort of a cleaner with the TB on the car and told me to keep the revs at 3500 or so. After a few minutes of this, i noticed revs a little higher, im talking at like 1100 or so when idling. At that time I didnt think much of it but went home. I noticed while driving cars wants to jolt forward. Well its started throwing a p507 code, which is higher idle than expected. Well I did research and found out about the relearn. Now heres where it gets tricky. I was able to do the relearn BUT after I shut the car down and restarted it would forget. After some more research, people said disconnect battery. Well that didnt help. Then most were saying TB has gone bad. I go and get a TB from the junkyard and its doing the exact same thing. Now im stuck with a TB that I probably never needed. So this is where i am at. I have no idea why its not sticking, any suggestions?

 

My symptoms were different. Only when clutch was pressed and moving it would jump from 1200 - 2000. When i came to a stop with clutch pressed it would settle at 1200. Weird thing happened today though, the SES light turned off, and miraculously it is idling perfect just a little high of where it should be 850-1000 depending on compressor on/off. Weird as hell. Hope it holds and now I just need an idle relearn.

 

As for you that does sound somewhat symptomatic but most people don't get that code when dealing with bad IACV as far as I read (extensively). I had trouble running the manual idle relearn too, i would maybe try a consult ii relearn at nissan and see where that gets you

 

Was it a an aftermarket IACV?

 

No OEM both times, and both sourced from Courtesy parts in TX

 

Idle has continued adjusting and now sits exactly where it should, not jumping, and no SES