Fat Slob
Member
For the last 3 times I have filled up, as soon as I start my Expy I get a check engine light, and when I get home I scan it and get code P0420 Catalyst system Bank 1(dont remember exactly what it says). I ONLY get the CEL light after I fill up, it doesnt happen any other time.
I just replaced all the coil packs and installed new plugs this past summer, and also had the drivers side CATS replaced this summer also Which side is Bank 1? Drivers or Passengers? Thank you!
Try a new gas cap.