1998 F150 4.2 V6 Code P1131

Question

Hi, I had code checked, engine light on, they say P 1131 I have checked for vacuum leaks cant find any. I don't think its o2 sensor only runs rough in gear. Any Ideas??? Help please.

Answer 1

Hi there,

It is possible you have a faulty or dirty MAF or a fault with the PCM, if you are certain there is nothing wrong with the sensors. Here is some more info for you.

P1131 FORD - Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Lean Bank 1

Read more: https://www.autocodes.com/p1131_ford.html