Ok i've got a 98 f150XL 4.2 i have changed my M.A.F, bank 1 O2 sensor,TPS,spark plugs ,wires, coil pack, egr line (the metal one) ,battery. But i still am getting a P0171 code and a P0171 pending and a cylinder 2 misfire, my IMRC,s are working and have no vac leak but sounds like i have a small exhaust leak, ..........oh and they are motorcraft plugs. what could cause this please help and thank you

 

Are you 100% sure you don't have a vacuum leak? Which 02 sensor on bank 1 did you change?

 

upstream and im 99 % sure

 

The misfire will usually cause a lean code in whichever bank it exists... I would shoot for a possible injector. Get a test light a CAREFULLY probe the power side of the injector and see if it flashes while it's running. If it does then you know you're getting power to it. Although that doesn't rule out a faulty injector.

 

Probe the backside of the injector connector while it's plugged in... sry lol

 

A dealership can do a fuel system test on your truck that will check each injector and be able to tell you if it's not opening enough or if it's sticking open using IDS. You can try pulling the plug out of that cylinder and see if the plug is wet from fuel or if you can smell fuel on it.

 

man your gonna call me a dumb*** for this but sou said to probe the injectors, well number 2 wasnt plugged in so i have been running on five cylinders since i got the truck,and now it is purring like a kitten thanks for making me look at my injectors you saved my a truck

 

Haha well I'm glad I was able to help kinda in a weird way. Don't worry I'm not gona call you a dumbass lol.