hello gentleman..

Im driving a 02 3.0L V6. 155k miles.

new parts listed...

valves and heads
plugs
wires
coil pack
alternator
belt
fuel filter
cleaned MAF

been driving it for about 2 months after the valve job and truck runs much better. this bucking and misfire under load comes and goes, has been like this well before the new valves. however it just now gave the the check engine light that says #4 cyl misfire.

any ideas.?

 

check for back pressure from clogged cat,removed O2 sensor and cracked exhaust at manifold and my 5/6 misfires quit.

 

cam sensor synchronizer ?

 

I did that before loosening the manifold and still had misfire,but if you've got miles it only costs~$70 as it turns oil pump. Did you clear codes, disconnect maf and remove oxygen sensor on bank2 to see if it stopped misfires?

 

ok... here is the conclusion for all of you.. i had a clogged cat converter. the very first one in line on the left side came apart and clogged up the second one in line. completely. ha. took it to a shop and they unclogged it and put everything back together. he said i needed a new converter to replace the one that broke apart. its $800. yea f that. im not planning on keeping my ride forever.

i do remember hearing a rattle in the exhaust in the past. i guess it eventually gave way. easy fix for $200. cheers gentlemen

 

Mine was the first one on the left also,but it hadn't come apart yet. You can get them new for ~$344 at autozone,and maybe less on line. I would say get a used one,but our wonderful US government has made it illegal for salvage yards to sell them. Check around on CL and you might find one.

 

Isnt it funny what a plugged cat and or exhaust system can do.