2 weeks ago I started my truck and it felt like ****. I could feel the truck sway from side to side (Im thinking this is what the TR220 is going to feel like) . Idled low, and then the check Engine light came on. So I drove it down the road and it smoothened up and was running fine. I took it to my buddies shop and his scanmaster said it was a #7 cylinder misfire. Cleared the code and it was fine. (Also at the time it happend it was wet and damp out so my buddy figured something just got wet. 2 days ago I was leaving Olive Garden the same thing happened again, but it lasted for 15 miles until I could get it back to my friends shop. It said the same thing #7 cylinder misfire. It was cold and damp out but not raining. He said I might need a new set of spark plug wires since they seem to crap out around 50,000 miles (I have 45,000). I am not going to get the crappy chevy brand, I will get some Magnacore ones if that is what I need. Or now Im thinking it might be a coil or something that could he cracked that is drawing in mostiure.

 

Could be wires or a coil, possibly even an injector. The oem wires are actually pretty decent.

 

Big cams require you to edit the misfire tables in your PCM or else you'll have all kinds of issues with the converter locking up or setting SES codes. You don't want to delete them entirely like we did in the "old" days of the LS1 but it doesnt need to be changed a bit to keep things under control. Your cam is borderline big.

Other than that. You could have a bad plug. Even if new they can have tiny cracks in the porceline and it will misfire. One of your plug wires could be bad.

Also, the Magnacore wires suck IMO. The fall off hella easy and were no better than my stockers. I run stock plug wires on my truck right now. I may upgrade with the new motor though since 18+psi has a tendancy to blow out weak spark. lol

 

Could be an intake gasket leak. We have seen many that will start to leak. Usually a little higher miles than you though. It will mostly show up on a cold start and throw a missfire code. The miss usually goes away after it runs alittle.

 

my truck did the same thing a couple weeks back, running real rough as if i had a big cam plugged the tuner in said cylinder 6 was miss firing, changed the plugs cleared the code now it runs better than before.