Check Engine Light Code P0300 On GM 2.2L and 2.4L

25 Responses

  1. sparky7366 says:

    well this is all fine and dandy but your not addressing a po300 even on accel and no other codes stored so I would assume that according to the diagnostic trouble tree that should be addressed first – since it is the most common problem and then I would adress the other problems as far as at idle only

  2. ivory says:

    Wat could cause my 09malibu to misfire po300

    • ProTech says:

      A lot of things can cause that, and that depends on what engine you have. Could be anything from a bad spark plug or ignition coil, to a wiring problem.

  3. kike jr says:

    hi i have a 2009 hhr 2.2 with cylinder 4 mysfire replaced spark plugs,coil packs, may u please help me.

  4. anna says:

    Have a misfire on 1st cylinder..after I’ve changed the spark plug it went away for a few days but the check engine light came back on givong the same error. .it does it when its idle amd than when I take off..I’ve also changed seals suspecting a leak to the spark plug. .didn’t help.

  5. Anonymous says:

    i have a 2005 cobalt and i was told it has low compresion after someone put something in my gas tank and the dealer ship is a joke. what is the problem. the dealer ship is jumping right to putting a new engine in. is their a cheaper fix

  6. marissa says:

    i have an 2005 chevy cobalt and i was told it has low compression and this is after someone put something in my gas tank. The dealer ship is saying its probably my engine but they only looked at it for 30 mins. They claim there is nothing in my tank or lines. my car will start but just stalls right back out unless you hold the gas down.so is the dealership right or is it something other then my engine.

    • Sam says:

      It would have to be something very bad in your gas to cause l;ow compression= very unlikely. Possibly diesel fuel in the gas could have caused that.

  7. mick says:

    2005 malibu, 2005, when engine is warm and not all the time, but temp guage just rises up past half, the engine will flutter at exhaust, loss of power, the cat was replaced. what do you think

  8. larry says:

    did i just leave 1

  9. Will says:

    2009 hhr 300 code. Shows up only when I start the car. Puff of smoke from tailpipe.

  10. bullworine says:

    for pontiac g5 if engine lights comes on and code reader says p0010 , it means chassis and body ground r not properly connected or grounded ….

  11. Kent says:

    I have a 2001 grand am 2.4L that recently got new piston rings and timing kit installed as well as all gaskets, coil housing, coil packing, spark plugs, and even fuel injectors, as well as fuel pressure regulator. not too long after I got a PO300 code and I cant figure out, could it be timing if so how can I check the timing. or MAP sensor it does not have a MAF sensor, it idles rough a little bit after start could you help?

  12. Sam says:

    2006 Saturn ion P0300 bad idling and misfiring bad under load acceleration also good at steady speed
    any thoughts on what to look at next, replaced plugs swapped coil and checked all electrical connections

  13. Gus says:

    Hi,

    When you wrote..” replace cylinder head and bad valves” you mean replace Cilinder Head Gasket & bad valves?

    Thanks.

  14. Calvin says:

    I have a 2005 cobalt with a po300 code reading ! My car has a lack of power and you can smell it flooding . Can you give me any advise onto the problem?

  15. Roger says:

    Just got my 2009 HHR fixed and here is what it was. Started surging, Service Engine Light came on and gave a P01100 code for Intake Sensor on front of engine so I bought new one and it ran good for about a week. Then Service Engine Light came on again and gave code P01100 again but lead to Intake and Exhaust Solenoids on top of engine. Bought and installed those. Ran fine for a day or two then while on a trip far from home at a station it started and killed. It would not keep running long enough to drive it. It was obviously missing. Had code reader with me and it gave codes P0101 and P0300. The P0300 is apparently a catch all code that GM must use for many things so it was very hard to pin it down. It did say something about “Air Flow or MAF” on my code reader. With just enough knowledge of auto mechanics to be dangerous I thought maybe it is the Air Filter since I had never changed it. Remember car is barely running and coughing and stumbling to even drive. I bought a new air filter ($12) and presto….. all problems solved. I had to clear codes manually but car is running like new.
    Like I said I just got done but I have all the faith in the world that the problem is fixed.
    Hope this info is helpful to others.

  16. Backyard Auto Mechanics says:

    Before you go spending lots of time and money….. change your AIR FILTER.

  17. Digital says:

    2008 Chevy Cobalt 2.2L – Did all the normal steps; moved sparked plugs, ignition modules & injectors to another cylinder and still a misfire on #4. Only thing replaced so far was the o-rings on the injectors. Checked for vacuum leaks and there are none.

    After the ignition and power steering recall replacement recently I had to replace the TCM after the transmission started acting up . There was a flutter shifting into overdrive and it wouldn’t stay unless I gave it a little kick. Since I didn’t have the time to work on it, I took it to transmission shop. The owner told me he was getting weird readings after forcing the TCC solenoid into overdrive. The trans was staying in overdrive, which meant no leaks in o-rings. Instead of trying to stick me with an $800 bill to replace the TCC solenoid, I suggested we get a TCM from the junkyard for $40. He couldn’t believe it solved the problem. I’m a tech guy and deal with computers all the time, however, they are little different on cars.

    Since there is no Ignition Control Module on this car and the plugs are fired by the ECM, I’m wondering what your thoughts are on that being the problem given the background of the TCM issue. An ECM from the junkyard from the same model car is $50. The ECM would need to be flashed with the correct VIN, if it solved the issue.

    Next step would be the compression test

    Any thoughts?

  18. TamayaTech says:

    Ok, REALLY NEED HELP , I HAVE A 2010 HHR LT WITH TROUBLE CODES PO302 AND P0300. I HAVE PUT NEW SPARK PLUGS IN , A NEW COIL, AND COIL WIRE CONNECTOR , EVERY THING THE DEALER SAID NEEDS TO BE DONE FIRST TO RULE OUT ANY OF THOSE POSSIBLE ISSUES. I STILL HAVE THE SAME CODES POP UP AFTER A FEW DRIVES AND IT SEEMS TO COME BACK WHEN THE CAR IS AT IDLE, PLEASE ANY HELP WOULD BE GREAT , I AM RUNNING OUT OF IDEAS.

  19. TamayaTech says:

    Ok, REALLY NEED HELP , I HAVE A 2010 HHR LT 2.4L WITH TROUBLE CODES PO302 AND P0300. I HAVE PUT NEW SPARK PLUGS IN , A NEW COIL, AND COIL WIRE CONNECTOR , EVERY THING THE DEALER SAID NEEDS TO BE DONE FIRST TO RULE OUT ANY OF THOSE POSSIBLE ISSUES. I STILL HAVE THE SAME CODES POP UP AFTER A FEW DRIVES AND IT SEEMS TO COME BACK WHEN THE CAR IS AT IDLE, PLEASE ANY HELP WOULD BE GREAT , I AM RUNNING OUT OF IDEAS.

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