Code PO300 engine misfire.
Thread Starter
Drifting
Joined: May 2005
Posts: 1,564
Likes: 19
From: Driftwood PA
Code PO300 engine misfire.
Check engine light came on today. Really rough idle. Light goes off and on but runs the same. 2001 36,000 miles, any ideas? [size=13px]How[/size] to go about finding this misfire?
Heel & Toe
Joined: Jul 2019
Posts: 17
Likes: 33
From: Gunter, TX
A couple of week ago I got a new to me 2003 ZO6 with 20K miles and within days I got the same error code and the idle seemed a little rough. Went through a number of different things and eventually pulled one of the spark plugs and found the gap to be 1.5X the spec. Got new plugs and wires and when I pulled the rest of the plugs they were all gapped incorrectly. Cylinder #7 took as much time to change as the rest added together but I got it.
No more error codes and the idle is good now.
No more error codes and the idle is good now.
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
I saw a broken valve spring caused pressure issues in the intake manifold causing random misfires (P0300).
Too bad it isn’t calling out a single cylinder hence a spark plug, wire, or coil… it’s a random cylinders.
I’d pull the valve covers and look at the springs.
Too bad it isn’t calling out a single cylinder hence a spark plug, wire, or coil… it’s a random cylinders.
I’d pull the valve covers and look at the springs.
