Spend your hard earned money for a good code reader that will record freeze frames in real time. Compare the frames with frames where the truck runs right and when it runs bad. The PID's will give them selves away to you as obvious malfs. Than you can graph them while driving to see the little buggers act up. The fuel system should constantly change back and forth from closed loop (rich mixture controlled by maf ) to open loop (lean mixture controlled by O2 sensors. ) It does this to control emissions and ozone emissions. If it doesn't go open loop look to faulty O2 or catz. All this time the timing will be adjusting anywhere from 7 degrees to 40 plus degrees. While the Maf will be going from .5 all the way past 11 under hard throttle and the 1st set of O2 will look like boing boings and the second set will be just lazily turning on and off. Thats if everything is good.

 

so i finally got mine running good turns out it was the coil pack. half of it was not working haha...

 

I was having the Same issues as James in the original post here with a few more complications. My truck had several codes thrown ~ P0303, P0315 and P0401.
303 and 315 are missfires that were easily fixed with new plugs, wires and coil pack.
401 is an egr problem that I will fix with a new egr valve and new DPFE
In addition to all of this my OD light was flashing. This was a more costly repair. Needed a rebuild on my tranny and while I had it out I replaced the Torque Converter as well. After all was said and done I spent about $2500 and the sputtering/Backfire is gone and my truck runs well.

 

Also I just wanted to say thanks to you all for posting your issues here. It helped alot!

 

I would check your O2 sensors see if that helps I had same porblem with my truck I replaced the 02 senseers porblem sovled

 

Before you do that theres a sensor under the air filter if you try cleaning I bet you 10 bucks it works what do you have to lose more than likely that is the pormblom took me in 12 ppl to guss at all the same things on my dad's my friend who just went to work at the ford deller ship came frist thing he clean the senoers under air filter in cheek engine light off in its got the power back

 

I took my yukon denali to several places that checked it one place thought it was either the coil or the plugs they eventually said it was neither and didnt charge me they said it was an electrical issue and recommended an electrical shop I took it there and they found the issue was somewhere in there power wasnt being sent to the engine after 2 days it works perfectly now

 

You do realize you’re replying to a thread that was started over 10 yrs ago and last post was 7 yrs ago.

 

Omg I didn't know that 😏😏😏🙊🙊🙊 ofcourse I do but maybe other people like me may need the answer