30thTAWS6

1999 Pontiac Trans Am completely stock that is showing codes
PO172 Fuel Trim System Bank 1 rich
PO175 Fuel Trim System Bank 2 rich

can anyone help?

30thTAWS6

anyone? anyone know where I can go to find out?

Catskynr

Code P0172 and P0175 is most often caused by a bad fuel pressure regulator or a bad fuel injector. You will need to do a fuel pressure test to determine which is exactly the problem.
It may have too much pressure or good pressure but leaking down into engine due to a bad injector or pressure regulator.

Also; the MAF sensor might be contaminated from: dirt, oil, silicon, spider webs, potting compound from the sensor itself, etc. When a MAF sensor gets contaminated it skews the transfer function such that the sensor over-estimates air flow at idle (causes the fuel system to go rich) and under-estimates air flow at high air flows (causes fuel system to go lean). This means Long Term Fuel Trims will learn lean (negative) corrections at idle and learn rich (positive) corrections at higher air flows.
This malfunction may or may not throw a DTC (Diagnostic trouble Code). If it does, the possible DTC's are: P0171, P0172, P0174, P0175.

30thTAWS6

thanks for the info