I have a 03 f150 xlt with the 4.6, started idling hard and cel came on. Pulled the code and it said misfire in cylinder 8 so I bought some lucas oil gas treatment and after a few days the shaking stopped and the cel went on. Now its back and even worse, saying I have random misfires in cylinders 2, 7, 8. pulled the spark plug and cop on cylinder 2 and they both look in good shape. Does this mean its a compression or injector problem? Also the rough idling will come and go randomly while driving, and almost stop in the mornings when I first start the pickup. Any ideas? I'm really at a lost here and don't know much about these triton engines.

 

when was the last time you got fuel? or changed the fuel filter

 

Just recently bought this pickup so Idk about the fuel filter, but its been about a week and a half since I've filled up with the lucas treatment at a stinker station if that makes any difference.

 

if you got gas at a little run down place i wouldnt be one bit surprised if you got bad gas

 

Its a chain in my area, not too far from one of the busiest intersections in my town. If it is bad gas what can I do to fix it?

 

pretty much just run in down and fill it again with some dry gas

 

Okay I'll give it a shot see if it fixes it!

 

Change the fuel filter.

 

Changed the fuel filter but it's still running rough. I noticed the EGR Pressure Sensor was damaged, one of the attachments for the vacuum lines was busted and the vacuum line was just floating around in the engine bay...could this of caused the problems I've been having?

 

oh yea..a vac leak will do it