Well about last Friday my check engine light went on, and the guy at autozone said that either my gas cap(?) or one of my hoses is taking too much vaccum? Anyway to fix this? And I did not get a word he said, so correct me if I'm wrong.

 

i bump for you

 

Did he tell you what the code was?

What's the year of car/engine/ECU?

Without that information, here's my best guess:

OBD2 Civics and Accords occasionally have problems with the evap purge solenoid, which is related to gas tank pressure. It's supposed to vent fuel vapor back into the intake manifold. If it fails, it will throw that code. If the gas cap fails, it will throw that code. If the gas tank leaks, it might throw that code. If the gas tank is overfull it might throw that code. If the ECU is going, it might throw that code. If you have a vacuum leak, it might throw that code. Lots of reasons.

I chased evap codes for 2 years, replaced most of the evap system, and went through every troubleshooting procedure in the Helms manual. Eventually, I figured out that my Civic does NOT like to be overfull. EVERY time I overfill it, I get a CEL. Also, for some reason on my Civic, the gas pump doesn't always cut off in time if it's running full blast.

I tell people that if you're getting a gas cap / evap CEL, the FIRST thing to do is run a few tanks of fuel through it, pumping about $1 less than full on every tank to make sure that you don't overfill. If the CEL doesn't come back, then continue being careful not to overfill. Pump the last gallon on the lowest setting, and don't top off. Since starting that, I've never gotten another evap CEL.

I still don't know why it does this. The car has 214K on it now, has done it since about 70K. I have no other symptoms (gas smells, etc) that would indicate a leak. I've just learned to live with not topping it off, as it NEVER gets an evap CEL if I cut it just a bit short.