: P0300

03-22-13, 01:42 PM
I've searched several times and didn't find what I need to see...P0300 code is being thrown and its driving me nuts! Only on cold start ups...I replaced on coil, plugs and wired...cleaned the MAF .as I do every time I change the oil...got on yesterday while idling...and feed back will be greatly appreciated...

03-22-13, 02:10 PM
Its a random misfire if memory serves. I got it from bad fuel once on my car. I always use Shell now. Also in my last car I got it from map/maf issues (on a bone stock car with 3000 miles). I used to get it after I ran the nuts off my old Cobalt SS from time to time.

Have you checked injectors yet? Poor atomization or incorrect fueling will cause a misfire as well.

03-22-13, 02:56 PM
This can be a very aggravating error code with which to deal because there are so many potential causes. See attached.

03-22-13, 06:46 PM
is your car tuned or stock computer? My car was throwing this intermittently with no symptoms after installing a W4M computer and it went away for good once I got a CKP (crank position) procedure done. It was only off enough to throw an occasional misfire and not the actualy code for that issue.

Like Darkman said there's a lot of potential causes.... check to make sure you have no vacuum leaks since putting your MAF back on, etc.