P0172= 1/1 fuel system rich.
P0175= 2/1 fuel system rich.
You probably know this, but rich means too much fuel. Or, not enough air. When was the last time you changed the air filter?
I would suspect something like a leaking fuel injector or a faulty MAP sensor not generating a code. Check the plugs, coil(s), and wires.
Saturday, December 10th, 2011 AT 3:25 AM