When I bought the truck, cylinder 4 and 6 were miss firing. Changed the coil, cap, rotor, plugs and wires. It ran perfectly for almost 2 months. Just last week cylinder 4 began to miss fire. I checked the plug and it was looking ok but, changed it anyways. Didn't help so i switched cylinder 4 with 6 to see if i had a bad wire.... then 6 popped up. Got a new wire cleared the code... now both 4 and six are showing. didn't do the trick. Anyone got any ideas? There isn;t really any lack of power except once when I gunned it to pass a car, it kind of jerked and didn't really want to go. Hasn't done that again though. Any help is greatly appreciated.

 

What kind of plugs are you using?

 

have you fixed your plenum yet ?

 

I put in the Champion copper plug's and I haven't been having any problems with the plenum yet.

 

#1) Have the cat pressure tested
#2) Verify the plug wires are properly routed per the TSB

 

Already re-routed the plug wires. As for pressure, I go do that today. I have to change the A/C compressor clutch and the idler pulley. May as well check the cat while I'm at it.
Speaking of that. I was planning on either gutting the cat or just taking it out all together. Once i do that, I'll have to move the two sensor's in front of the cat, right?