Lean Code Help - P1131 & P1151
 

My mach is running rough, small popping on passenger side.

Finally threw codes P1131 & P1151, Lean codes.

I did some internet searching and lots of results, but alot were after changes.

I have made no changes in 5+ years.

Its a NA bolt on car with JLT, long tubes, tune, and off road H pipe.

My guesses are vacuum leak, dirty mass air, bad fuel pump, dirty fuel filter or bad O2 sensor.

Any insight or similar issues to save me some time fixing?

Thanks,

Keith

Do you have a tuner or a scanner you can Data monitor with? I would check fuel pressure at the rail, look for leaks, if you can data monitor your fuel trims you can spray some carb clean in any areas that may have a vacuum leak and look for changes in the data monitor


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Re: Lean Code Help - P1131 & P1151
 

Might have to try, never data logged before. I have the tuner.

Re: Lean Code Help - P1131 & P1151
 

Is that a lean code for each bank or what? If so I’d look at stupid stuff like your JLT connections, pass side valve cover to JLT line and driver side pcv line. There’s also an evap hose from pass fender to TB that tends to rot