At a loss....

[jonezin_nj]

Ok, I have a 2004 expedition, 5.4L, 4WD. I'm at 156k. A couple of months ago I noticed that the engine would bog down if I stomped on the gas. Sometimes it would back fire and the CEL would flash. I replaced the bank 1 sensor 1 O2 sensor and it seemed to help. Now it is running real rich on the bank one. There seems to be a knock at idle coming from the same side. I have replaced and checked everything I could find in the forums and it still runs like crap. Here's what I have done:

1. replaced both upstream O2 sensors
2. replaced all the plugs and 2 coils
3. replaced fuel filter
4. replaced MAF sensor and air filter
5. I tried removing the bank 1 upstream and plugging the hole with the old O2 sensor while leaving the new one plugged in to see if it was the cat. no dice
6. scanner pulling rich and lean bank codes on both banks along with cylinder one misfire.
7. I didn't find any vacuum leak in the boot from the pcv as suggested in another thread.
8. Cleaned the new MAF sensor a # of times with MAF spray cleaner (no dice)

I replaced the cylinder 1 and 2 plug again because they were fouled (maybe due to running rich). I pull the injector plug on cylinder one and there is not a real noticeable drop off in the idle like there is on cylinder 2. You can smell its running rich, and its just idling terrible.

Any thoughts?

 

[rburch]

Have you tried unplugging the battery to relearn the air/fuel and idle?

 

[jonezin_nj]

gonna do it right now. Will check back.

 

[Thermo]

jonein_nj, I am betting that you have had a fuel injector or two fail on you. If you are only getting a trouble code on the one side, then I would put a new fuel injector into cylinder 1 and see how the truck runs then.

 

[jonezin_nj]

unplugged pos terminal 15 min. No dice. found cylinder 3 plug burned up

 

[jonezin_nj]

do you think its blowing past the injector, thermo?

 

[jonezin_nj]

the CEL reset after i unplugged the battery

 

[toms89]

unplugged pos terminal 15 min. No dice. found cylinder 3 plug burned up

Define burned up.

Is it electrical connection for injector, coil or is it the spark plug?

Post photo if you can.

If its the spark plug a bad injector could have caused lean condition burning the plug up in that cylinder. Depending on the degree you may have damage to the piston or heads.

If its a electrical connection it could just have been loose connection. May have to replace connector and device. (coil or injector)

 

[jonezin_nj]

Cylinders 2 and 3

 

[outkast]

hard to tell the the pic is so blurry, but are they black and wet? if yes, then you are fuel fouling.

sooo...either you have a spark issue (two bad coils??) or a fuel issue (two bad injectors??)

swap the coil from the cyl> (you are saying 2 and 3 but you really mean 1+3?) and see if the other plug then fouls.

could be an ecm problem, but lets hope on injectors or coils. make darn sure the coils are plugged in and firing.

also check for a blown intake gasket....the backfire leads me to believe that