01 Ford Expedition Problems...Please Help!!!

So my mom has an expedition and it started driving rough and i pulled the code P0307(cylinder 7 misfire) off of it. So i replaced the spark plugs and erased the code and it started driving perfectly. Then a couple of days ago it didnt start when she came out of the gas station when she went in to just get a drink, so i go down there and it doesnt even try to turn over or no click sound...nothing. So i hookup jumper cables and finally get it to want to turn over but couldnt get it to start. i saw that there was that acid corrosion stuff on one of the terminals and so i cleaned it off and it fires right up and starts driving perfectly. Now yesterday she calls and says it is driving extremely rough and hardly wanted to idle so when she gets home i scan it again and i get 4 codes...P0307 again,P0174( System too Lean(Bank 2)), P0306(cylinder 6 misfire), and P0308(cylinder 8 misfire), everything is hooked up right. I dont know if the coil packs are bad or the MAF sensor is bad and creating the to lean affect and causing the misfires. i plan on testing the MAF sensor tomorrow. Any help would be greatly appreciated. Thanks...Mike

 

i tried going on a expedition forum but nobody is even on there. Oh and Cylinders 6,7, and 8 are on the same side of the engine(driver side)

 

Good luck but that's a ford for u

 

Intake manifold gasket maybe? Has to be something that affects just that side of the motor. Hopefully you put the same exact plugs in it that Ford had to begin with.

 

At our shop we work on a lot of Fords and we change coil packs like theyre going out of style. Per the Ford trainer, the correct way is to replace all 8 coil packs and 8 spark plugs, replace the fuel filter, clean the throttle plate and bore.

Most likely the reason why you have the lean bank 2 code is because of the misfires. All the O2 sensor knows is to read oxygen levels in the exhaust gas, so if there are misfires on bank 2 (cyl 5-8) the O2 sensor will see a lot of oxygen because of incomplete combustion and ASSUME it is lean.

It's probably not the MAF because that would affect all cyls. If money is tight you could try replacing coil packs one by one but you have to make sure that the plugs are good first.

 

check the idle air control valve, my ford acted like that not expensive and only two bolts to remove .......

 

You've got a couple of bad coil packs. This is fairly common with Triton V-8's (coming from a former owner of one).

 

Definitely sounds like a bad coil pack.

 

thanks guys for the help, i was figuring it was bad coil packs as well. So i guess i will just get 4 new ones and replace the 4(5-8 cylinders).