my vibe threw a CEL, after 2 1/2 months

[vibebob]

started the vibe Thursday to go to work and the CEL came on. checked some stuff, opened the gas lid and gave the cap a quick twist . . kinda felt like it wasn't snug, but not loose either.Went to O'Reily's on Saturday and the guy checked it and first thing he did was go to the gas cap. pulled it off, looked at the ring, replaced it and said its all done. he cleared the error.a loose gas cap can cause a CEL ? ! if so, why didn't it clear when I tightened the gas cap ?

[Raven]

It takes a few cycles to clear itself. You can always disconnect the battery for 10-15 minutes and it clears the codes as well.

[joatmon]

as part of the emissions control, the car tries to keep a slight vaccuum on the gas tank. Any gasoline that evaporates will be pulled into the engine and burned, instead of venting to the atmosphere as pollution. The car's computer will sense if it is unable to set and maintain a vaccuum on the tank, which it can't do if the gas cap is not on tight, it doesn't know why it can't set the vaccuum, so it lights the light to let you know that it sensed something wrong. It will also store a diagnostic code to let someone know what kind of problem it sensed.I don't know why it doesn't clear automatically. A lot of the CEL codes take several normal cycles of tests before it decides the problem really is fixed. Maybe so that intermittent problems won't be overlooked. The tests run to clear a CEL vary depending on the failure the conputer sensed. After long enough with no problem, the light will go out, but the stored code will be kept so you can go back later and see what that light was all about. Often the quickest way is what you did, get someone to hook up a code reader, get the code and clear it.In these cars, severe issues will cause the CEL to blink, a blinking CEL is really bad news. A large number of the non-blinking CEL causes are related to emissions control systems, stuff you should get fixed, but not engine damage imminent serious

[zionzr2]

Quote, originally posted by Raven »It takes a few cycles to clear itself. You can always disconnect the battery for 10-15 minutes and it clears the codes as well.unfortunatly in most cars it takes SEVERAL times to clear itself. The Battery tip is great if you dont have anything to reset the code yourself. If there is a real problem the CEL will return. At least in some of the Chrylser products they are seperating the CEL with a gas cap light. But same deal it takes several cycles to clear it unless you reset it buy battery or code reader.