Scotty I've got a random misfire code recurring, I've changed wires,plugs,pcv valve,fuel pressure regulator, still happening, mainly at high speeds,it will high rev then bam the check engine light flashes and run like crap,fouls the #6 and #2 plugs,what in the world is causing this? I read a forum saying GM changed plug style and to no longer gap at the 0.060,that they're not to be adjusted from the factory 0.040, could this be the problem, improper gap?
2000 suburban 4x4,no cats,k&n air filter set up,only registers the po300 code @50mph or faster never in low speeds
you mean P0300. Po300 doesn't exist.
You mentioned a K&N filter set up. If you put oil on this filter, you will screw up your intake system and cause misfires. Only use a dry filter. Worth checking out.
Check for leaks- it could be a vacuum leak or a head gasket leak. Check also the camshaft and crankshaft sensors. I would also have a compression test done on the engine.
368,552 miles on this 21 yr old motor
I've checked all vacuum leaks,none at all pcv valve was bad, replaced it, stopped the backfire I was getting,I'm thinking crank sensor,but not sure, always willing to ask other opinions
Check the FAQ
That could be it, I'll clean the oil out of it and see if that fixes it, I've got the cleaner kit
I didn't say anything about oil.