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Service lite came on check it out and found Code PO442

What does this code mean and how do I fix it


  • edited November 2010

    This code indicates a leak in the car's evaporative emissions system.
    The first thing to check is the gas cap.

    If the gas cap is tight and the gasket is in good condition, then further testing of the evap emissions system is necessary in order to find the leak. Unless you are skilled in this type of work and have the equipment necessary, you need to take the car to a qualified mechanic.
  • edited November 2010
    Evaporative Emission System Leak Detected (small leak)

    It could be your gas cap, it could be a small leak in the gas tank or a hose, it could be a bad solenoid valve, and so on.
  • edited November 2010
    just had the same thing happen to me. my son borrowed my car and put in hi test gas( no need for that in my 2000 olds alero) had the same code. car was running fine .my manual said if you change brands of gas this might happen i took the gas cap off and put some grease on the neck filler and on the inside of the gas cap. i did fill it up with regular gas. i drove it the next day and the light went out, the same thing happen with my wife's car (2004 buick lesabre) drove that for a couple hundred miles and the light went out. as long as the lights not blinking there is no major problem-- hope this helps --best of luck
  • edited November 2010
    Why would a comment that using "hi-test" gas could cause a P0442 code appear in a owners manual or any where else? an evaporative emission system an fuel octane don't cause conflicts with eachother.
  • edited November 2010
    old school -- i did not say " my manual said code po442 causes this problem" it did say changing brands ( which happen to be hi-test) might make service engine light come on-- i went to auto zone to get PO442 and it told me the usual things that po442 could be---gas cap vacuum leak,,, etc. hope this helps clear up your answer
  • edited November 2010
    Simply so our readers will not get confused, changing the octane of the gas you put in the car will not cause the "check engine" (or service engine) light to come on.
  • edited November 2010
    How often does you son borrow the car? How often does he put in gas?

    Could be the son, not being a "frequent filler", mis-handled the gas cap.
  • edited November 2010
    i know the hi-test did not cause the problem i said" changing brands "that's what my manual said --how much more plain do you what me to be???
  • edited November 2010
    only because his car was being fixed --- so i let him borrow mine--- to get to work-- he lives 30 miles away--- so i very " never' let him take my car. AND YES HE COULD HAVE MIS-HANDLED THE GAS CAP
  • edited November 2010
    Let me ask you to make it clearer, what code do you think would be set simply by changing brands? many here don't even go for the different brand idea (thinking it is all the same and just marketed different).

    We have to remember impressionable people read what we are writing and the first rule is "do no harm". What I mean is, people have enough misconceptions about that "check engine" light, we don't need to add more to the list.
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