Been playing with my 2005 Nissan Frontier 2.5L (engine is QR25DE) with a 5spd transmission and 180k miles. Dealing with P0507. Idles around 1500 RPM, then when it gets good and warm (minimum 20m driving), the idle will surge from 1500 to 2000, then back to 1500, then back to 2000...
Stuff I've done so far:
1. Replaced all sparks and changed intake box air gaskets
2. Replaced PCV valve (was failed, truck has been burning oil)
3. Checked for vacuum leaks twice, none found. LTFT is close to zero all the time.
4. Cleaned throttle body front & back (it was filthy, this helped acceleration noticeably)
5. Cleaned MAF sensor
6. Left negative terminal off overnight (ECU)
7. Performed idle air relearning procedure many times
This truck doesn't have an EGR (uses VVT) nor an IAT.
What would be the top things to try next? Trying to hit low hanging fruit first. Thank you!
Stuff I've done so far:
1. Replaced all sparks and changed intake box air gaskets
2. Replaced PCV valve (was failed, truck has been burning oil)
3. Checked for vacuum leaks twice, none found. LTFT is close to zero all the time.
4. Cleaned throttle body front & back (it was filthy, this helped acceleration noticeably)
5. Cleaned MAF sensor
6. Left negative terminal off overnight (ECU)
7. Performed idle air relearning procedure many times
This truck doesn't have an EGR (uses VVT) nor an IAT.
What would be the top things to try next? Trying to hit low hanging fruit first. Thank you!