Just helped my father-in-law change the motor in his expedition. After getting it done it has a miss when under a load. We hooked a scanner up to it since the CEL came on and the code are 1131 and 1132. I know there is a pretty long list of what this could be but any help would be appreciated. He done had it at local garage for a couple of hours with no luck just a bill.

 

what did it have and what did you swap into it?
P1131 Lack Of HO2S11 Switch - Sensor Indicates Lean
P1132 Lack Of HO2S11 Switch - Sensor Indicates Rich
thats weird the same sensor indicates rich and lean. i would think its the sensor. is there a vacuum leak? and/or a injector problem?

 

The shop said the injectors tested fine just might be dirty. It had the 5.4 originally and was replaced with a 5.4 from a salvage yard.

 

Mannn , I can't remember what that means, and or why... Shoot , I usually don't forget what I remember, but it was quite awhile ago.

JM - Check back in a little while - It will come to me. Or - Quintin knows this one, that's where I got it from.. Ah Hell, check back later J.

The 02's toast IMO..

 

i'm stuck on it just being a o2 sensor since its just the one sensor and the way its reading. maybe someone will think different. was the carbon and stuff cleaned up inside the motor? you may want to run some seafoam through it or have someone run a motor/carbon vac on it.

 

Alright, thanks guys. I'll let you know what I find out.

 

while your waiting for someone to come up with a novel thought, have you checked the wiring to make sure it didnt get pinched? just something to eliminate.

 

Yeah, didn't see any pinched or damaged wires.

 

Make sure the upstream O2 sensors aren't connected backwards.

 

wouldnt that throw 2 sensors?

 

So we cahnged th O2 sensors and he said the engine was clean when he put it together. Still having the same problem. Does it matter that the engine was originally built for natural gas? He changed everything over from the motor he took out for regular gas so I would assume everything should work.

 

Does anybody have any other ideas?