ok 2 days after i got the truck i got p0306 erased it then 20 miles later i got an o2 sensor code then i ordered one and drove the truck 4 days code never changed during this time same o2 code no others then 4 days go bye i get new sensor and replace it then same time i did the plugs wires coil rotor cap and oil change just got the truck i always replace every thing when i get new vehicle to be safe ok now i start he truck drive within 20 miles i get that damn p0306 code ???? i have checked compresion in all cylinders its good ive checked the injector its clicking good i imagine its fine im aware of the tsb for plug wire routing its not that and also the truck runs great yah only notice the mis at idle and even then its barely there hardly hear the engine studering and it barely stunns the rpm gauge the truck seems to run great the mil is also solid its not flashing please help i cant figure this one out for nothin

 

o its the 360 motor 5.9l

 

If #6 is misfire I would first recommend swapping that injector with another. It could be clogged on the inlet or faulty (rare, but possible). Move it to an odd bank, such as #1. If the misfire moves, then it's the injector; otherwise, if it continues then I start to suspect a clogged cat. Those can be pressure tested at a muffler shop.

 

i dont think it is the cat it looks kinda new and i banged on it seemed solid but ill try the injector thing and also wouldet the cat make a multi cylinder mis i wasthinking injector prob to but hate messing with them

 

well i have went ahead and swaped the injector i cleaned them all the best i could also when i was in there and the fuel rail but still p0306 i swapped 6 with 1 same crap i donno what else it could be i guess ill rip the throttle body of there and clean the hell outa that next well see if its that i just feel like i am gonna spend a whole lot of time taken crap apart and its gonna be something very simple that im over looking

 

A clogged cat will make #6 and or #8 misfire due to back pressure. Just because it looks "kinda new" on the outside doesn't mean it's not clogged inside. You could also have a problem with the plug wire to #6. Are your plug wires routed properly?

 

Is your engine a 5.9? Did you run a full compression test with ALL plugs removed and TB at WOT? If so, what were your results for #6 compared to the others? Sounds to me like you've got the crack b/t the valve seats like I had. To rule this out, run a leak-down test on #6 and listen for air escaping at TB or exhaust pipe.

 

A cracked valve seat completely slipped my mind as a possibility.

 

Unfortunately, his symptoms sound just like mine did. An irritating miss at idle that smoothes out when the throttle is opened. That's why I suggest saving time and money and just cutting to the chase with the leak-down test. When I did mine, air was rushing out through the TB. I was in denial for a long time before that, lol.

 

well how hard would it be to put a new head in there like a junk yard one with valves and all that in already is it as easy as taking off the intake pulln the head clean up and throw the new head on and torque it down??? i have never done a head before but i am pretty confident i could in this truck looks easy could some one type down steps for me ?????? im stil not sure its thehead but im sur my luck is about that good lol i got a steel on this truck i figured sommin would have to be done ive done alot already includng the water pump that was easy as pie how could i do the leake down can it be done with a comprssion tester??? and i have no compressor