i have a 2000 4.6L. the truck will barely get out of its own way and 6 codes showed up. P0358, P0174, P0303, P0306, P0307, P0308 4 of them are misfires and the one is system lean(bank 2) and the other coil malfunction or something. at first it just started with cylinder 8 misfire so i bought a new plug and coil and it made no difference. after them put on it is still reading misfire on that cylinder. does this have a fuel starving problem? bad injector or dirty fuel filter? i just dont know where to start. cause one thing is pointing me towards coils while the lean part is pointing me towards injectors or fuel filter. i did just put a new gas tank on about 2,000 miles ago and never changed filter. give me some ideas please thanks!

 

I think you might be onto something about the gas. Maybe you have a restriction.

I would start there, because that would explain why you are having all those codes at once. If it were just one cylinder, then maybe focus on the coils.

I would definately change the filter after the new tank. Who knows what may have been in the tank or knocked loose when you changed it.

Maybe check the pressure on your fuel rails to make sure you are getting all the fuel you need.

Stone

 

ok yea hopefully its just a fuel filter. i will try to get that in tommorrow after work and go from there i guess. thanks for the reply. also another reason it seems like fuel because if i am going up a hill and have it floored it cuts in and out like it gets power for a split second then dies out again. again thanks for the reply!

 

ok put a new filter on and injector cleaner in her. the filter was def dirty but still runs real bad. cleared codes and ran it for a few miles and still misfiring on cylinder 3 and 7. i think im just gonna buy all new coils and plugs and get it over with. i am gonna switch some coils around too and see if the codes move with it.

 

Man.....

I'm stumped....

I still think it is something to do with fuel delievery. This will cost you a little money, but have you checked your fuel pressure on your rails while under way? I had a similar problem, it was much more subtle that yours, but it would lose power and 'slip' driving up hills and powering up on ramps. More so while towing, but all the time nonetheless.

Well, turned out it was my fuel pressure regulator. It took me 4 months to figure out. I replaced my plugs and my coils also....nada. Finally I hooked up a pressure gauge to my fuel rail and took the truck for a spin. Sure enough, whenever I would experience one of these 'episodes' I could plainly see it on the gauge, my fuel pressure had dropped 20psi or so. My truck was starving for gas, plain and simple.

I replaced the gas pressure regulator and BOOM!!! Instant fix, instant power boost, etc. It's like a whole new truck.

Anyway, good luck!

Stone

 

Thanks for this post. I had the same codes coming up and my 2002 Ford F150 was running really sluggish. I got a new Fuel Pressure Regulator at O'Reilly's for $50 and I bought the snap ring pliers ($5) replaced the fuel pressure regulator. That fixed the lean code P0174 on bank 2 then I went to work on my coils with a wire brush and I took the crud off the connectors. That fixed all the other codes I was getting. Very happy with the results and responsiveness now. Thanks again.

Doug