I have a 2001 F-150 with the 5.4L. 165k miles all original SP injectors and COP.

CEL is coming on and code typically shows 'misfire on #5'. Sometimes it shows 'too lean on bank 2'

Engine idles rough and drives with hesitation and shaking.

I was originally thinking bad COP or plug but the too lean code makes me think injector or maybe fuel filter.

Any thoughts?

Thanks!

 

Which misfire DTC did you get ? Lean DTC is canceled when misfire is present.

 

fuel filter.

 

How many miles on the plugs and what brand are they?

 

Yea, it could be a fuel problem. That's what your suppose to check first when diagnosing, - fuel pressure @ the rail. Although, a pressure problem usually picks on cylinders furthest from the pump, like #1.

 

165k miles. Still have the OEM plugs in. I know, I know....

The system too lean code was P0174. The misfire was P0305. Also had a misfire detected on #4 today.

Thanks for the replies.

 

So 304 and 305 ? Did they get wet ? Check the plug chambers for water or coolant.

 

I'd go with the fuel filter too, it's probably time.

Also at 165,000 you don't have a bad plug, I'd say they were pretty good. But alas they are worn out now.

Like jbrew said check for moisture and change the plugs and filter. In fact it might be getting close to needing some regular maintainence.

 

165k is way too long to have the original plugs in.....

 

Lol i change mine original plugs 200,000 then my coils in 230,000.

 

That's good for you (not really)