The other day as I was driving to work I got the message "Tighten fuel cap" in the odometer display. The check engine light didn't come on. When I went to lunch I didn't get the message but the check engine light was on. When I turned the truck off I reinstalled my fuel cap. When I left, the light was still on. It has been on for about 70 miles now but haven't received the "tighten fuel cap" message again. I also have yet to get it scanned to see what the error code is. I have the repair manual and have read a few other posts on how to handle the issue if it is the solenoid that controls the tank pressure but I had a few questions out of curiosity since I have yet to check the repair manual. The primary one is if the check engine light comes on and the problem is fixed, will the light go off on its own or do I have to disconnect the battery or something to reset it? The other thing I was wondering is if these issues with gas tank pressure are relatively common and expected for a model as old as mine? BTW, I have a 2005 Silverado with the 5.3L with ~96k miles. TIA.