i've got something wrong with my #6 cylinder and i can't figure it out... A/F gauge shows my right side running rich and i can smell the un burned fuel coming out the exhaust... these are the things that i have eliminated-

fuel pump
fuel injector
spark plug
plug wire
bad fuel
coil pack is firing at idle..

but the thing is it will run like **** and miss and sputter untill the truck warms up. at WOT it'll barely run up to 3000 rpm and then at like 3200 rpm it's like it become a whole different truck.

i need help because it's killing my gas mileage.
what do ya'll think it could be?

 

How did you determine #6? Thru a compression check or just a misfire code? At the very least a compression test is in order to verify the mechanical condition of the engine. A little more backround would be helpful, like when did it start or did you do a mod that caused it? Maybe it's a bad catalytic converter.

Dave

 

I think he ran through high water...

My guess is a possible burnt valve, I agree, do a compression test

 

it first threw a multiple random cylinder misfire code.... so i cleared it and then the SES light came on again and said Number 6 cylinder misfire so i started to check things that it could be.... my mods e-fans, LT's, CAI, Tune, full cat less 3" exhaust, vette servo... no mods are new...

 

Coil pack could fire at idle and still be F'd up. Do the compression check with all the plugs out and the TB open for an accurate reading. You can rent a tool at Autozone if you don't have one. If that turns out ok then it's gotta be electronic or fuel

Dave

 

hard to tell without a compression test