My check engine light came on yesterday, and was wondering if anyone knew of anay common reasons that this is happening. I bought a new air and fuel filter to try, and was thinking that since gas is so expensive these days that since I've been using low grad gas rather than medium grade that might be it too, but other than that I don't really know where to start other than taking it to the shop.

------------------
'97 F150 XLT XCab, 4x4, Stepside, Black, 4.6L
Fiberglass Box Cover,
Bug Deflector, GTS Tailight Covers, Ford Factory Running Boards,
(2) 10" XTant subs w\ MTX amp (really pounds!!), Lifted Rear Seats 1" So The Subs Fit Under, Factory 6 Disc Changer, And One Cute Blonde In The Passanger Seat!!!

Pickup's Better Half: '68 Ford Galaxy 500, 2dr, Hardtop, Fastback

 

I had the same thing happen to me. It ended up being the Pcv valve and that cost about $1.50. So try that. Mine came on at 65k. At least give it a try. Good luck.

 

It could be any number of sensors that could have gone bad you need to get a code detector and hook it up to see what codes show up then look them up in the book and replace what ever the code shows to be bad.

 

Mine has come on three times over the past three months. First time was after sitting almost a week at the Houston airport. They replace the fuel cap filler neck. Second time was withing about 30 seconds of filling up after a road trip. Third time was last week, again after sitting for a week at the airport, came on on the freeway on the way home. All three times I cleared it by disconnecting the battery cable. Don't know why it keeps happening. Any ideas?

 

Mine just came on this evening and my truck only has 1,050 miles on the odometer!!

I drove to the nearest dealer (Montebello Ford) and since it was closing time, the service sup asked me to bring it in tommorrow morning. Hopefully, it is something REAL minor picked up by the sensor.

 

According to the service guy, there was an "evaporator leak" caused by the gas cap not properly capped.

Frankly, I'm skeptical. The cap was tightly on, like it has always been. I bet the diagnosis didn't come up with any codes, so they simply turned off the check engine light.

 

The "loose gas cap" answer is common. I had the engine light coming on in my GMC often and was told by two GMC dealers that the cap was the problem. They just kept resetting it without fixing anything. The last time the dealer charged me $100 to reset the light. Finally I took it to a certifed private shop where they found a bad gasket on top of the fuel tank. He also told me that emission problems are covered under a 7 year/70,000 warranty here in Wisconsin. When confronted with this info, the guy in the GMC shop (who also handle Ford) stared blankly at the bill, then stammered and claimed I was not charged for anything under warranty, even though he had the bill in his hand. Not a good "spur of the moment" liar. That was the end of my involvement with GMC, I traded it off two months later. The point of all this is that they may be trying to avoid warranty claims by blaming it on the owner for not tightening the cap.