I have a 2001 Nissan Frontier SE/XE w/ 3.3L 6Cyl engine, no supercharger, 4×4 automatic transmission. I have 4 codes on it right now, which are:
Haynes Repair Manual's description is: Catalyst system fault (left bank).
Mechanics diagnostics description is: Bank 2 Oxygen sensor behind catalytic converter.
Haynes Repair Manual's description is: Idle Air Control Valve or circuit fault.
Also the same codes pending:
I took my truck into the shop to fix the rough idle which I believe was causing the P0505 code and his pending twin. Apparently the little metal arm from the Fast Idle Cam and Thermo Element that makes contact with the Throttle Lever (to maintain proper idle during cold operation) was bent out of position. Most like bent during the removal of the Intake Manifold when I had to replace the Knock Sensor.
After a half completed diagnostic test and a $157 charge to bend the metal arm back into place, the mechanic reset the codes. The truck idled and ran like before. I didn't notice if the Service Engine Light was on before I got home but it was on when I parked the truck.
These codes are, for lack of better words, stuck on my On-Board Diagnosis system. I have an OBD-II code reader which allows me to erase codes as well. Which I have done multiple times, but these stubborn codes don't seem to erase. The tester instantly checks for codes after erasing previous codes. As soon as I erase the codes I keep watching the tester (I do not turn the key to the off position or anything of the sort) and the codes are still there.
I drove 120 miles to try and do a drive cycle or two, hoping that the computer will reanalyze the sensors and relays. Didn't work.
I had a dead battery and replaced it but still the codes are there.
Any way that I know on how to erase a code, I have tried, but they never go away. The computer doesn't even do its system check then turn the Service Engine Light on for these codes.
I don't want to pay another mechanic to do another Dyno on my truck just for them to do basically nothing like the last mechanic.
Is there something I am missing?
Is there something wrong with the Powertrain Control Module?
Is there something else I can try?
Wednesday, January 9th, 2013 AT 4:27 AM