Please if anyone can help I would be very thankful. About two weeks ago the check engine light comes on I check the code to lean so I replace both upstream and both down stream,same code so I put new plugs, pvc, clean mass air flow sensor,replaced a few vacum hose's Check ERG and replaced the gas cap. Now after all that work at idle it feels rough and when driving it feels rough, and now when i'm at a loght the idle drops really low to almost where it wants to stall. Now to day i'm getting the codes p1 151 p1 131 o2sensor circuit low voltage and last po156 o2 sensor circuit malfunction but the check engine light never came on? The codes 171 and 174 are gone. The truck is a 1998 f150 4.2 engine

 

You may get more help if you post this in the Engine forum. You posted this in Site Announcements. This forum is for announcements about this site.

 

there is a huge forum on this posted in the either the Engines or V6 Engines forums. check those out, because mine was doing the same thing, and i got tons of help over there.

 

thanks for letting me know i am new to this site