So pinks cobalt has been saying "check gas cap" on the driver info. So I tighten it and it goes away. Now note this has been happing since mid september. We don't drive the car whole lot anymore since we got the beater car. So wed we go out and the car won't even start. Engine turns over but dosent fire. Eventully it fires and starts and we drive up to the local auto zone and replace the gas cap and I cleared 2 "evap large leak" codes and then the car is fine. We drove it the rest of the day no problem. Now tonight we get in the car to go out and not a mile down the road the "check gas cap" comes across the driver info and on comes the check engine light. So has anybody run across this problem?? I'm thinkin of just droppin it off a the dealer but you know how are a cold air intake and lowering springs cause every problem. HELP PLEASE.....thanx.

 

Check to see if there is any dirt around the seal. I got a CEL on my old car from that.

 

did that already and replaced the gas cap.

 

I had an EVAP code for a long time. Turned out to be the vent solenoid.

 

Did your warranty cover it?

 

look around and see if you can find a crack in an evap line...

 

i had the EXACT same problem. Its the evap silonoid, your warranty doesn't cover it.

 

how much will that cost to get it repaired? We were told that the emissions had a 10year 100,000 mile warranty

 

Maybe it does, I have a 2.0 SS/SC, and im over my bumper to bumper, it costed 182 total.

 

SHe has an extended bumper to bumper warranty so we should be good????

 

it is part of emissions and it is faulty not do to your part. is a piece of the fuel system that vents the excess vapors form your fuel tank. she should be good.

 

Good to know, we really don't want to be putting a whole bunch of money out on the car since its going to be put away for the winter.


Its just weird it started mid September and then never had a problem again till Wed. then changed the gas cap, all codes went away and now it says check gas cap but no check engine light.

 

The car puts up the Gas Cap message when it falls the gross EVAP leak test and doesnt fail any other EVAP tests.

If youve got the PZEV option it MAY be covered under the 15/150k PZEV warranty, but thats only if Pennsylvania honors that(they dont have to) If youve got a good ext warranty its proly covered. Its NOT covered under the 5/100 powertrain warranty unless its a failed fuel tank or fuel pump module.

It could be a bad fuel tank pressure sensor. I see these go bad on all kinds of stuff, and they usually fault to atmospheric pressure, so the ECM thinks that the tank doesnt hold vacuum ven if it does.

If youve got access to a scantool, go into the EVAP parameters and see what it says under fuel tank pressure, it should say "0.00 in H2O"(or within .02) with ignition on and gas cap OFF. if it doesnt theres a problem with it. When you blow into the tank(with an air nozzle on an air compressor) the number should go positive, IE: from 0.00 to 0.54, 1.09, etc... if it shows a negative number or stays at zero youve found your problem(or at least part of it)

 

I'd bet money it's the solenoid