Check engine light/evap emmisions control

Hey my check engine light came on my 1997 escort 2.0 sohc a few months ago, soI got it checked at autozone and it said that it was my evaporative emissions control. Well I put it off for a few months and wasnt driving my car much. Then the other day I decide to go back to autozone to make sure I knew the correct part, of course on my way there the check engine light just magicaly goes off after I stop to get gas. :mad: :mad: :mad: I'm sure the problem isn't gone, but the obd II wont detect it if the check engine light isn't on. I also noticed that sometimes when I stop, the car idles rought and the rpms spike slightly then drop back down. But any help would be appreciated cause I don't wanna pay for a part that wont fix the problem.

I think on newer Fords if the gas cap is not air tight then you will get a check engine light. I wonder about this since it went out after you got gas?

Yeah but I had filled up several other times before it went out, and its still idleing sort of funny. But I have heard that untight gas caps can cause a check engine light. I tried testing the sensor before but the chiltons repair guide I have confuses the hell out of me sometimes.

Hey my check engine light came on my 1997 escort 2.0 sohc a few months ago, soI got it checked at autozone and it said that it was my evaporative emissions control. Well I put it off for a few months and wasnt driving my car much. Then the other day I decide to go back to autozone to make sure I knew the correct part, of course on my way there the check engine light just magicaly goes off after I stop to get gas. :mad: :mad: :mad: I'm sure the problem isn't gone, but the obd II wont detect it if the check engine light isn't on. I also noticed that sometimes when I stop, the car idles rought and the rpms spike slightly then drop back down. But any help would be appreciated cause I don't wanna pay for a part that wont fix the problem.

On the CEL codes there are hard codes and soft codes. The hard code is a problem that has occurred and continues to be had. The soft code is a one time problem that no longer exists. If you had a soft code it would automatically erase itself after 40 some starts of the engine. I not too sure of how many times it is, but you get the idea. If you've got a CEL code and it is a soft code and you don't want to wait for 40 some starts for it to go away, you can delete it by disconnecting the negative terminal of the battery for 15 minutes.