[05ramthunder]

Wife drove my truck tonight for about 10 minutes. She informed me about 5 minutes before I was headed to bed that the check engine light came on. Of course I couldn't just go to bed so I checked the code. P0300 random intermittent misfire. What would the most logical explanation for this be so I don't throw a bunch of money out and waste my time chasing gremlins? Seemed to idle a little rougher than usual when I checked it out and was a little hard to start. Thanks in advance for the help.

 

[hemiheaven]

I know on a Chevy I had.....intake manifold gasket.....

 

[05ramthunder]

Reset the light and have driven it for 3 days on back roads and interstate to try to replicate the problem. Runs smooth as can be and no CEL since the initial post. Not complaining that it is running good now. Just strange.

 

[Hasiuk]

Could be anything really. The rough idle could be bad plug wires or a vacuum leak all the way to the MAF/O2 censors going out or being faulty. If you want to start somewhere with out spending any money, check all the connections on your MAF/O2 censors and make sure they are secure, inspect your plug wires and make sure there are no cracks in any of your plug boots, even the smallest crack can cause the plug to arch and misfire. Pull all your plugs, inspect them. going from there you can run a fog machine through your intake and see if there is a vacuum leak, if thats not it, I would replace the MAF/o2 censors, and if that doesn't work, your head gasket.

Just my two bits, but start with the small things =\

 

[TommyJ22]

I'm having the same problem. Getting the general misfire code p0300. Put some Heet and a full tank of gas in it and it went away. That was a month ago. Put half a tank of gas in it today and drove it to the dentist. Came back out and it started misfiring again. Does my problem pinpoint a problem or will I have to run through all the common problems associated with misfiring?

 

[RamRod37]

I'm having the same problem. Getting the general misfire code p0300. Put some Heet and a full tank of gas in it and it went away. That was a month ago. Put half a tank of gas in it today and drove it to the dentist. Came back out and it started misfiring again. Does my problem pinpoint a problem or will I have to run through all the common problems associated with misfiring?

Because you said you put gas in today Im wondering if Gas Cap maybe bad iv heard of that happening