Ok so back story is ford replaced all coil and plugs except #5 & #6 a year ago. Last month I was getting P0305 so I swapped the coil and all is good.

Now today I was towing my boat to the lake and was going up a hill in town and just started losing power. I was crawling up the hill at 10mph and CEL was flashing. Limped to the lake, went boating came back and fired up the truck and seems to be running normal. Put the boat on the trailer and go to pull out and couldn't make it up the ramp just revved to 2k ish. Had to put it in 4 LO to get up the ramp. Started heading back home and could feel an obvious loss of power. Started going up a hill and had to floor it to get the tranny ti kick down and as soon as I hit 3k it started pinging. Left the boat at a hotel and headed home. Still showing lack of power and pinging at 3k. Got to a very steep hill by my house thats about a 1/4 mile climb, started at 40 and by the top i was crawling at 10mph.

I get home and scan for codes and p0305 popped up. Went to the parts store and exchanged the coil for a new one. Pull out on the road and floor it and as soon as i hit 3k it started pinging and losing power again, plus another flashing CEL.

Ran the codes again and this time got p0305 and p0171. Any ideas? I'm going to try to pull the plug tomorrow but doubt I will be successful.

Other than that it seems to run good other than a little rough idle and down on power. this is an 05 with 130K on the clock.

 

The P0305 code means that cylinder #5 is misfiring, it does not mean it's a bad COP causing it. The P0171 code is a lean fuel/air mixture code. Considering the two codes, my first though would be that the fuel injector for cylinder #5 isn't working. Have you also changed the #5 spark plug, or did you just assume it was good? Swap the #5 and #6 spark plugs to see if the code moves to #6. If it does then change the plug with a new one. If the code remains with #5, then swap the #5 and #6 injectors for the same reason.

 

I'm in the process of pulling the plug now. Hopefully it doesn't break. Also isn't p0171 bank one which is passenger side right?

I have been trying to find the Pcv valve to check it but I can't find it for the life of me

 

Well the plug is giving me a hard time like i figured. took a break to let the pb blaster to set in. Decided to pull the drivers cat cuz I knew it was on its way out and sure enough it was broken apart. I cleared the rest out and put everything back together. Cleared the codes and took it around the block. still detonating at 3k, stumbling at idle and now I have P0305 and P2197.

Gonna go get some starter fluid and see if i can find this leak.

 

Ok I think I fixed the ignition issue.

Changed #5 Spark plug and another coil. So overall all the coils are a year old or newer and the same for all the plugs except #6.

Not getting anymore misfires or circuit errors.

Now I am getting P2197 - O2 Sensor Stuck Lean Bank 2 Sensor 1

Does This have anything to do with my gutted cat? I figure I would get a inefficent cat error. I don't wanna go throw an O2 sensor at it if its not gonna fix the problem

 

Did you use the scan tool to clear the codes?

 

Yes I did everytime before I took it for a test