Alright, this is my first post but I've got a problem. I just bought my 02 Silverado 2500HD. Its got the 6.0L and it started running funny the other night on my way home. I checked the code and it came up with a Random Multiple Cylinder Misfire. If anybody has any insight or could give me a few tips they would be greatly appreciated.

Thanks

 

Look at plug wires, plugs, etc...

You don't say how many miles on the truck. If it's near or over 100k, change the above.

 

There is a large grounding lead on the front right side cylinder head (just below the oil fill tube), remove the bolt (or nut) that secures this ground lead and check for corrrosion, this is very common, if there is corrosion remove it with a toothbrush and Coke Cola and reassemble.

 

Yeah its getting pretty close to 100K. Its got 79,500 and with it being a larger truck I'm sure its had some fairly rough miles on it.

 

Alright, I appreciate the help with my truck but I found the problem. Apparently while I was at a local pool hall someone decided to be funny and unscrewed my gas cap and I didn't realize it until I went to put gas in my truck last night. I filled up and tightened it down and it ran perfect.So anyone with this problem, check there first.

 

First time that I have heard of a loose fuel cap setting a "Random Multiple Cylinder Misfire" DTC.

 

Yeah it surprised me too but from what I can tell that is what caused it because when I sealed the gas gap everything ran great again. To be honest I'm glad it was as easy as that though. Beats having to go through and check everything one by one. Thanks for the tips though everyone,

 

Hell yeah.