Had a check engine light issue and couldn't figure out what the heck was going on. Took the truck in and found out it was a emissions issue, the gascap was leaking. Got a new gas cap and the check engine light is gone. But now get a GASCAP message on my odometer that wont go away when I start the truck.

 

They should have reset the computer when they fixed it unless it isn't really fixed and has a leak in the charcoal canister area.

 

Thanks, that may be it. The repair shop says you have to drive it for at least 25 continues minutes with at least a quarter tank of gas and it resets itself.

Mine did not and now the check engine light is on again. Going to have to take it back in.

 

Could be one of the hoses on the evap canister by the tank. The system is not holding pressure and they put the gascap thingy in there because 90% of the time it is because the driver filled up and either left the cap off or didn't get it on completely. You are in the other 10% where there is another problem.