I bought this convertible a couple of months ago as my daughter's first car and have been working on it ever since. After a major rebuild due to rod knock, it was time to tackle the "little" remaining problems. First off was P0601 code (PCM checksum), which I ordered from a refurb outfit in south Florida. It took 3 to get one that didn't kick the same code. Now I am getting P0172 and P0175 (rich on both banks), as well as P0700 & P0740 (TCC not locking).
The car runs great. I tore it back down again today enough to check fuel system, etc ...no leaky injectors, pressure is normal, couldn't find any vacuum leaks, MAP is clean and operational. EGR seems OK, no apparent exhaust leaks or intake air restrictions. I'm stumped, and considering taking it to the dreaded dealer for diagnosis.
Freeze-frame data gathered just running the car in the garage after reassembly:
DTC for which Freeze Frame was Stored: P0172
Fuel System 1 Status: Closed Loop
Fuel System 2 Status: Closed Loop
Calculated LOAD Value: 6.67 %
Engine Coolant Temp: 127.40 °F
Short Term Fuel Trim - Bank 1: -25.00 %
Long Term Fuel Trim - Bank 1: -25.00 %
Short Term Fuel Trim - Bank 2: -18.75 %
Long Term Fuel Trim - Bank 2: -25.00 %
Intake Manifold Absolute Pressure 11.55 inHg
Engine RPM 704.00 rpm
Vehicle Speed Sensor 0.00 mph
While I doubt the tranny codes are at all related, I am wondering if the refurb PCM company even programmed / flashed it, and that may be what is causing the fuel mixture codes?? Any suggestions are more than welcome!