Durango 2003

I have problems with the SUV when I put the computer I get system too rich code P0172.

First of all, you have to see if the engine works stable; since there are several causes that cause a rich mixture; oxygen sensor, 02 circuit signal, return signal signal of 02, tps sweep signal, MAP sensor, ECT sensor, EVAP purge solenoid, high fuel regulator, fuel pressure has to be 44-54PSI or 365-434kpa, mechanical problems, PCM (computer), contaminated gasoline, motor oil, or coolant, check that and then tell me.