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2011 Chevrolet Suburban - Gas cap

Check engine light came on about two weeks ago on my 2011 Chevy Suburban. A day or two later the car flashed the “tighten gas cap” notice. Husband said no big deal but I don’t listen so here I am.
Took the car to get the codes and they gave me the following: PO442, PO455
I purchased a new gas cap and will wait and see what happens after going through the recommended driving cycles.
They did say the codes given meant a large leak and a small leak.
If it is just the gas cap, will the light go away on its own?

Yes it will go away on its own… IF it is just a gas cap. If the light stays on after about 3-4 days, have the codes read again and see if the P0455 persists. The list of possible causes for a P0455 is;

  • Missing or loose fuel cap
  • Incorrect fuel filler cap used
  • Fuel filler cap remains open or fails to close
  • Foreign matter caught in fuel filler cap
  • EVAP canister or fuel tank leaks
  • EVAP system hose leaking
  • Fuel tank leaking

So the bottom 3-4 are likely next checks.

Thank you! Also forgot to mention sometimes the ac does not blow cold. Don’t know if the two have anything in common or if it’s two different problems happening at once. If I turn the car off and turn it back on - usually that’ll fix it.

The AC is a separate problem.