P0172 1997 Ford F150 - check engine light is on

Question

What would you check for first if the check engine light is on (code P0172)

Answer 1

Hi there,

The code is for a rich mixture on bank 1 of the engine. I would start with the front O2 sensor. This can cause the fuel trim to be rich. If the sensor doesn't solve the problem then the next step would be checking the fuel injectors.