P0171: Oxygen Sensor System Too Lean Fault Bank A
P0507: Idle Speed Control Engine Speed High Fault

I need to get this fixed soon cause there gonna suspend my plates pretty soon.Any advice would be nice. Mike

 

anyone?

 

I've been researching my problem and have come to the conclusion that my IAC is bad.What components sum it up.How would I be able to trobuleshoot an answer.I have a 58mm bbk Tb.Does this change anything&tb bypass free mod. Mike

 

P0507 is idle system high, IAC responding. Sounds like you may have the 58mm TB idle stop screw adjusted incorrectly. What RPM does it idle at? Apparently it is significantly higher than the stock PCM setting of 550rpm in gear and 650rpm in neutral.

P0171 is fuel trim lean, drivers side. Apparently the long term fuel corrections on the drivers side have max'd out at 160, and are unable to control what the PCM sees as a "lean" condition. Typical causes include exhaust leaks before the O2 sensors, misfires, and faulty O2 sensor/wiring.

It would probably be helpful if you could put a scanner on it and check the IAC counts and TPS voltage at idle to try and sort out the P0507. Then log some data while driving and look at which cells the long term fuel corrections are max'd out (or at least verify that they are max'd out).