Random misfire?
 

Getting a CEL with random misfire and misfire on cylinder 2 and 6. My SA suggested I swap coilpacks with 1 and 4 and see if that changes the misfire. And a friend suggested it could be the knock sensor plug/wire from when I had a cat replaced a few weeks back. I cleared the code once two weeks ago and it came back today with another random misfire code. Anyone else got any other ideas or has this happened to you in cold weather? It's not running weird and I don't hear anything strange. No loss of power or any other indications of a problem. Btw this is on an LLT.

Thanks y'all!

Try the coil packs and spark plugs and see if it helps, if that doesn't help it go away than try getting fuel system and injector cleaner hooked up to your fuel lines to see if maybe it's just gunked up. If that doesn't work than you may have to open her up and check your timing chains. Thing that worried me is that you have two cylinders doing it and not just one. Usually one means spark plug and coil

This just happened to a customer that brought his cts into service. Was only cylinder 4 and we changed his spark plug and coil and was good as new.

mentioned this on the V6 LLT forum aswell but run dry gas and injector cleaner through it before anything else took mine 3 days to clear same two cylinder misfires like the other guy said gunked up probably because of the moisture from the fuel blend change. BTW Ethanol sucks so much in our cars for this.

If you have a ported intake manifold, make sure the filler is in one piece and not inside the runners.

Alright I grabbed some of this. Will run it through and see if the code comes back since we cleared it. If the code comes back will swap coilpacks and check knock sensor plug/bolt. Attachment 586928

Good luck! Keep us informed. :popcorn:

When the light came back on today it didn't show 2 and 6. Just random misfire.

I'm really thinking the gunk and moisture from fuel is a possibility. The car has 90k miles on it and I've only run seafoam through it twice and it was a long time ago. Gotta start maintaining now that she's aging.

:laugh:

I have had the same thing happen to me, I have 60,000 miles on mine. With some research, I found out that my K& N CAI, was fouling my MAF sensor. This was then causing this CEL. I got some MAF cleaner and sprayed my sensor and it has taken care of it. Because the air filter has oil on it, the oil gets on the sensor causing the fouling. Performance hasn't been effected, just that annoy CEL.
http://youtu.be/aJLNQcFosSo

I may spray the MAF with cleaner too. I have noticed a reduction in my gas mileage lately too; more than the usual drop with winter fuel blend.

That is probably your foot hammering the gas because it's so much fun to drive fast. That seems to be my problem lately. :laugh:

^ This