2007 Chevrolet Cobalt Q&A

2007 Chevrolet Cobalt Question: My check engine light has been on going on two years now.

It codes as a cylinder 3 mis-fire. I had all of the spark plugs changed and the check engine light is still on. It took 3 inspections before it finally passed. When the gas tank is full It feels like it runs better and I don't feel it misfiring. Has anyone had any experience with this? -
Answer 1
Possible weak fuel pump, have seen that before. -
Answer 2
try a higher octane gas next time you fill up. -