Hi Guys,

2003 Ford F-150 4x2 4.6 V6

Service Engine Soon Light Came on Today

I scanned it out with my generic scan tool. It could not tell me what the codes meant because they are ford specific. They Are.....

P1131 and P1151

Both came in conjunction. Anyone know why they mean, or what caused them? I have not cleared them yet. I would rather fix the problem first.

The truck drives just fine, starts good, and idles/accellerates like it always has.

Thanks!

Here ya go.

P1131
Lack Of Upstream HO2S Switch, Sensor Indicates Lean, Bank No. 1


P1151
Lack Of Upstream HO2S Switch, Sensor Indicates Lean, Bank No. 2

Looks like you probably have a vacuum leak.

I have seen Ford Maf sensors cause this combination of codes with no symptoms like, as in your case, then suddenly cause a momentary stutter or hesitation then act perfectly normal again. All this without throwing a MAF code.

Great info, Thanks Guys! I will look into it and report back.

Is this a 4.2 or 4.6 if its a 4.2 v-6 check the hose from the PCV line going to the intake, u can't see it but can feel it , the elbow collapses and gets a small hole in it .( vacuum leak ) u can buy a new hose from the dealer...seen this alot...thats why the codes are from both banks....good luck

2003 Ford F-150 4x2 4.6 V6

Service Engine Soon Light Came on Today

I scanned it out with my generic scan tool. It could not tell me what the codes meant because they are ford specific. They Are.....

P1131 and P1151

Both came in conjunction. Anyone know why they mean, or what caused them? I have not cleared them yet. I would rather fix the problem first.

The truck drives just fine, starts good, and idles/accellerates like it always has.

Thanks! Is this a 4.2 or 4.6 if its a 4.2 v-6 check the hose from the PCV line going to the intake, u can't see it but can feel it , the elbow collapses and gets a small hole in it .( vacuum leak ) u can buy a new hose from the dealer...seen this alot...thats why the codes are from both banks....good luck