I've been trying to fix/diagnose my 5-speed 2001 P11.
First, I noticed one day as I was putting it in park, the car was idling kind of high. Oscillating slightly. I turned it off, and when I came back to start it up it went away.
About a week later same thing happened as I was pulling into my driveway. Only worse and then I got a check engine light. I didn't have a OBDII scanner, but I ordered a WiFi one that I could use with the DashCommand app for iPhone/iPad.
I worked on the car that week-end with the battery unplugged and it cleared the code. Check Engine Light hasn't returned but problem persists. Car only does this in neutral or low gears.
From my research, I'm leaning towards the IAC as this is a well known issue for 2000-2001 Nissans, however I'm not getting the P0505 code. I also took out the ECM and the board looked fine i.e. it wasn't fried.
What do you guys think about cleaning the IAC? Also, if I remove the IAC to clean it will I have to do an Idle relearn?
I don't just want to start replacing parts and sensors willy nilly.
Here's what I've done so far:
Replaced Cap and Rotor (Didn't initially change the spark plug wires because the resistance was still good, but I'm going to anyway)
Cleaned Throttle Plate really good with a wire brush
Replaced O-Ring on Distributor
Removed ECM to check for fried components
Disconnected MAF and started car to check MAF
Disconnected TPS and started car to check TPS