2004 f150 5.4 147,000 miles, just bought the truck, it had a misfire on cylinder 4, dealer replaced cop and all was fine, recently was checking torque on all plugs due to a fuel smell in cab, cylinder 6 was super loose but all are tight now but i couldn't get to number 4 so decided to do it the next day, truck was running great like brand new and slighlty reduced the fuel smell. Started on cylinder 4 today took the cop off (which is supposed to be new) and checked the torque on the plug it was tight. Put every thing back together (including the computer I had to take loose to get to the plug) and made sure all three computer plugs were back in correctly, evey thing back together start the truck and it cranks a little longer than usal but starts and immediatly is running rough, driving it is bucking at highway speeds and running like crap...took everything back apart 3 times and reinstalled and it's stI'll bad. I'm getting three codes through the torque app p0304 (misfire on 4) p0171 lean bank 1 and p0136 misfire at startup first 1000 rev. I drove with the torque app on and no more codes but still bucking if I'm watching all cylinders on the app in graph view all are up and down except 4 it's just a straight line across the middle...any ideas

 

Did you crack the plug ? Was the boot and spring ok ? Is the COP plugged in ? Did you mess with the fuel injector on 4 ? I would remove the plug and inspect. You can swap things to #3 and see if the DTC follows for troubleshooting purposes.

 

"... if I'm watching all cylinders ..." - on torque app, What does that mean. I do not know about any OBDII PID or PIDs that you could bemonitoring'.

You have an excellent diagnostics tool in Torque Pro. But Ford doesn't present live misfire counts by cylinder on any OBDII port for us. Take a look at MODE $06 (The "Test Results" selection from the front screen) and give it time to run all test. The results will give misfire counts by cylinder, current drive cycle and last 10 drive cycles.

 

I didn't do anything with. The injector but I did unplug and reply to make sure after, the cop I moved it to another and the problem remains and code come up now only the cyl. 4 misfire and the misfire at start up. I didn't remove the plug only put the wrench in it to 25lbs which it clicked just right after I put pressure on it, if I did crack it would it visually be noticeable is it removable or is the bottom portion now down In the engine.. I now do not have the lean bank one code

 

Here is the plug i dont know if that helps

 

Also to add, the truck had plugs done 400 miles
ago

 

It helps to pull pcm and bracket off firewall on passenger side . You need to air blow crap out of there . Plan on cleaning cly tip area out with carb cleaner the carbon breaks new plugs and screws up heat range of plugs . Forget gas additives cleaning that out .
Make sure you let carb cleaner evaporate ,you don't want to hydro lock cyl .
Use new boot and spring . Put dielectric grease on both ends of boot . Use new plug, new boots ,clean tip of coil . Take it easy starting plugs with fingers, these are aluminum heads, don't want to cross thread . These plugs are hard to deal with so don't cut corners .
Plan on replacing all before 50k . No matter how long its been since someone has done plugs, do you think someone else can take the time to do it like you should . Loose blowby plugs are a common complaint, it ruins boots and plugs . . Double check torque .
That plug looks like carbon blowby on it ,hard to tell . Get rid of it . My labor is worth more than the cost of new parts . I don't want to have to go back twice .

 

^^^ X3 -- even before you get as old and stiff as I am!!! lol