I have a 2007 F150 4x4 STX with the 4.6 liter engine. Engine light remains on after the following have been done:

1. Full diagnostic shows "rich" for both Bank 1 and 2 sensors before the catalytic converters.
2. No vacuum leaks, no intake or throttle body leaks.
3. Mass air sensor cleaned.
4. New fuel filter (within the last 6 months).
5. No restriction in either of the catalytic converters.

After running a while, the truck has a very rough idle and the fuel mileage is horrible. The engine starts stuttering when given a good throttle.

I am at a dead end and would appreciate any tips.

 

Sometimes if we disconnect/unplug the MAF sensor and the condition goes away , the sensor is defective and not working correctly.