I went to Canada ove the weekend in my moms van, and let her drive my car, and when I came back she tells me that the service engine soon light is on. I took my car to the dealer and when I came to pick it up 4 hours later, the mechanic tells me that the problem was that my fuel cap was not screwed on all the way, and the computer reading indicated different pressure, or something along those lines. What kinda BS reason is this. Anybody else had this kinda problem.

 

I've heard of such failures before.

Check the seal on the gas cap...if it looks damaged, you'll need to replace it. Otherwise, there might be a pressure sensor problem.

 

Believe it or not the gas cap will cause the same problem on most cars today. I think on the Saturns you won't even be able to start the car when it detects the pressure problem. It's happened on my co-workers Honda. Of course they can clear the light by holding the trip meter reset and turning on the car.

 

Wow interesting I would have never guessed that this would cause the problem

 

I want to say that it started with OBDII. Some sort of emissions deal or something. It's common on all cars though. THIS TIME they weren't blowing smoke up yur you know where.

 

loose gas cap will cause the ECU to trigger the code for an evaporative system leak or some other evap system code....

 

I was warned several times by the dealership when I picked up my 02 to be careful of this (or of starting the car when the cap was open, to say reset the mileage counter).

 

I read somewhere that HALF of hydrocarbon emissions were caused by non-sealed fuel systems in old cars. Gas gets evaporated before it has chance to burn and causes even worse damage to atmosphere. That's why they programmed ECUs to trigger SES light in modern cars for loosen gas cap.

Mike.

 

The Same thing has happened to me twice. When I went to the dealership, they told me that it was my gas cap not being screwed on tightly, honestly I dont beleive that, I think it might be a faulty sensor , but I am no mechanic.

 

I have actually had this happen to me once on my old 1998 Nissan Frontier. The cap was just loose. Also, my friend recently had it happen on his 2002 Jetta GLS, because the retainer strap for the gas cap got caught in the threads of the cap and didn't let it go on all the way.

 

Swallac2- You are exactly right, its an OBDII thing.. Regaurdless of the make, any car that has OBDII, this will happen too. In MASS, the state inspection now pressure checks your gas cap to see if it holds... If it doesent, you fail..

STEVE