P0170 code-Fuel trim malfunction. What can it be?
'98 Galant - Check engine light is on - Code P0170-Fuel trim malfunction. I replace the gas cap and added fuel injector cleaner to the tank, and checked for vacuum leaks, erased codes and drove to reset computer. At 67 miles light came back on, Code P0125-Insufficient coolant temp for closed loop fuel ctrl. So replaced the thermostat, refilled coolant and bled off air. Drove again and after a few miles, light came back on. Code P0170-Fuel trim malfunction. So what else can it be? Money is tight this time of year, so hopefully someone knows or has an idea of what to check and how to check it. Any help would be greatly appreciated.
The MAF looks brand new, not dirty at all. Have also replaced the fuel filter. It on the other hand was pretty bad, but the check engine light came on again. P0170. It seems to be getting worse. The mileage to reset the computer is shorter til the light comes on. Engine runs great. I'm puzzled???