The message centre on my 2001 Pontiac Bonneville SLE with 30,000 miles on it
began showing "Check Gas Cap" yesterday. I reset the warning, shut off the
car, removed the cap and gave it a visual inspection, made sure that the
mechanism inside the cap moved in and out and then put the cap back on. When
I restarted the car, the "Check Gas Cap" warning came on again. The car
appears to run normally, with no RPM surges, etc. Has anyone else had this
problem? Do the gas caps actually screw up or is this a computer
malfunction? All and any advice would be appreciated.