mideerslayer

Will a clogged /dirty fuel filter cause a 2002 f-150 5.4 to run like poop when engaged and trying to drive?

Sitting at Idle it is fine, but as soon as I engage the trans and put a load on it, it boggs down and runs horrible

I am doing plugs and Cops, and cleaning the Maf sensor

No steady codes, they come and go One time its the o2 sensor, next time its the maf sensor and then after clearing them there is nothing

I picked the truck up over the weekend from a dude who had a heart attack and he said he was chasing this issue.

I am also going to replace the flange gasket on the pipe between the manifold and exhaust pipe as its leaking

I have ruled out vaccum leaks, it did sit for a few months so I put 1/2 can of seafoam thru the brake booster vac line and the other half in the tank. After that it really start to idle a lot better

Jbrew

Yes to your question.

Big Ed 1

Why dont you just try putting on a new filter?
Might be due for one anyway.

mideerslayer

I plan on it, I was just curious if it would cause issues.

I did find one of my Fuel Injectors leaking today so I am wondering if that is the main issue.

Thought I smelled fuel yesterday when I was looking around the engine, today I started the truck and heard something so I looked and the back Fuel injector on the drivers side was spraying fuel everywhere

I planned on replacing them anyways as they look old and to get to the back plug and cop it would be so much easier if the fuel rail was removed

Big Ed 1

Your lucky it didnt catch on fire!
On my 99 I found that taking off the wheel well insert makes changing plugs easy. But I have a different engine, but that did make it a lot easier then working from up top.
The wheel inserts come out easy, if you need new clips they are available. There are a couple of screws too that hold them on.

JCR 56

He has a 5.4 V-8, the plugs are on top above the valve covers so removing the inner fenders would not help.

NFortin1966

If you are going to replace injectors, I highly suggest Motorcraft as aftermarket can vary in spray pattern as well as volume by quite a bit. Also make sure you replace with the same color code as the ones that you are replacing. Replacing with the wrong color code will cause more issues than what you have now. Toi tell what color code you have, just look at the originals as they will have a colored stipe or band on them.

Another thing that can cause the problems that you are experiencing is clogged/clogging cats.

Johnny Paycheck

Which is probably caused by that leaky injector. Or injectors. But, OP hasn’t revealed the codes that came up, so that help is gonna be limited.