Hello I bought my 03 f-150 V6 with the dealership having to fix the o2 censors on it. About a month later the service engine light came back on. I went to my local advanced auto and had them pull the code up and it said it was the u2 censor. I've went about two months without fixing it. Is this bad? I also went back to advanced auto to find if taking the truck to a dealership would be better than trying to have my girlfriends dad, who is qualified to do so, fix it. The person At the desk processed to tell me that it might not even be my o2 censor and that this is a common mistake a lot of people make thinking it is when it's another problem. He said my truck might be running to lean or rich. Please enlighten me! Much thanks and appreciation!

 

I'd take it back to the dealer and accuse him of installing a bad sensor just to see what he had to say. If he is a stand up guy, he'll replace it if it tests bad.

 

Ok thanks for the tip. But really the dealership hasnt helped out at all with the whole situation considering I bought it from a Hyundai/Chrysler dealership and they had to send it off to a Ford dealership just to get it fixed. So they won't touch it unless I take it to where it was fixed. They even said they don't know if the ford dealership will fix it anyway! Worthless unhelpful people!

 

How many miles... Sounds like you have a IMRC leak.. Google 4.2 IMRC

 

100,600K. It starts fine and seems to run great! Can't tell if I'm losing any mpgs. Only thing I can say it's doing is when it's warming up is that the rpm's rev up and down a little bit. Then it stops doing it after a few seconds. Like I said they changed the o2 and a month later the service light came back on. I had advanced auto turn the light off just to see if it was coming on for no reason but a couple days later it came back on and has been on since.

 

Ok last night I looked very closely and saw that my air intake had no clamp on it so it was actually unattached to what sucks I'n the air from the outside. So my engine was getting it's air supply for what ever air is under the hood. Not the outside. Could this be my problem and causing my engine light to come on? A simple hose clamp?

 

Only if it is after your MAF, if not than no.

 

Maybe... I would fix it either way... If its reving up and down it does sound like a vacumme leak somewhere

 

Ever since I put the clamp on it it's pretty much stopped. Idles down nicely now. Just need to see if that's what's been causing my engine light to come on now. Thanks though for all the info lately though guys. Joining this forums been very very helpful and makes me feel better about myself getting rid of my mustang for a good old truck

 

Idling up and down could be TPMS too right?