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Thread: P0300 Code

  1. #1

    Default P0300 Code

    I have 02 Trailblazer I6 4 X 4 and I am getting misfire codes.

    I was getting misfire code of p0306 and i replaced a ignition coil. However I am now getting P0300.
    I was having problems with rough idling and engine lights so i changed the spark plugs first with ac delco iridium.

    Guess first question is,, how hard on the car is it to drive with random misfire? It doesnt run very bad just when standing still. I was needing to drive somewhere thats about half hour away.

    Actually, its only when i turn the heater on that it gets really bad. If heater is off its less like to throw SES light.


  2. #2
    TRPLXL2's Avatar
    Join Date
    Jan 2009
    Norwalk, Ohio
    Blog Entries


    I have a 2001 S-10 that has had to date 529 misfires combined off of all 6 cylinders, I have put 50,000 miles on it and never got a code. The guy at the GM dealer asked me if I had a light and I told him NO, he told me to let it go until I got a light and I still haven't gotten one. I have an auto x-ray scanner that I keep in the truck, and each time I drive it that number keeps going up and up! I know that it sounds stupid, but I don't see a point in taking it somewhere and paying some guy $100 an hour to play process of elimination with my bank account as long as it's still running. Good luck with yours, I hope it works out for you.
    2004 Chevy Colorado
    LS1 5.7 swap/TBSS rear axle swap

  3. #3
    Jr. Mechanic
    Join Date
    Dec 2008
    Gettysburg, Pa.

    Default p0300 random misfire This site may help.

  4. #4
    Jr. Mechanic
    Join Date
    Dec 2008
    Gettysburg, Pa.

    Default p0300 code

    Sorry, maybe I should have linked you to this page so you don't have to wade through the whole site to find what you need. Go down to "misfire trouble codes" and click on "random misfire".

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