so ive got a 2001 f150 5.4 and ive got a #6 missfire code popping up ive already changed the cops and plugs im thinking it could be an injector any ideas?

 

Start with the easy.. Swap the injector with #5. How long ago did you change the plugs and was this miss always there before the plug change?

 

no the miss started before the plug ond cop change and the code hasnt gone away its been abt 2 weeks

 

Does the truck idle rough or has a misfire while running?

 

idles a little rough not terrible and seems to be ok all the way through the rest of the throttle

 

Swap the #6 injector with #5 see if it moves. If it dont compression test cylinder 6. if it does move replace the injector..

 

I got the same problem in my 2004, I have swap cop and injector with #5 also spark plug. Code keeps coming up but goes away when it warms up sometimes but no check engine light. Did a compression test came out perfect. the engine idles a little rough in cold start but once it warms up it goes away. Im leaning toward a clogged injector port on the intake manifold or maybe the ECM.

 

swaped the injectors problem is still there going to do a compression test now all i can say is since ive had this truck im not impressed by the ford 5.4 by any means ive always been a ford guy but this might puss me towards switching brands

 

can i do the compression check on the 6th cyl without pulling all the other plugs? since i know how much fun it is to do them lol

 

You can just do that cylinder but you should get an average. Start with that cylinder if it reads no lower then about 110 lbs your probably ok.

 

Let me guess, your not impressed with a 10 year old truck with, I dunno, I'll just take a guess at over 125k miles. Probably hasn't had a lick of maintenance other than the fluids being changed...is built up with carbon and runs like crap, sensors are starting to fail, cats are plugged up from all the fuel additives from trying to keep it alive....Coolant is rusty, brakes are squeaking, rear end is dragging from the 10 year old burnt fluid and clutches, 4x4 stopped working from rotted out vacuum lines and the rear window is leaking. And now that it has a misfire, your not impressed?

I'm just messin....

Sometimes chasing mechanical issues can be frustrating, but every vehicle you jump into will be the same. That and sometimes we just have bad luck.

I know you said the miss was there before the change but what plugs and COP's did you use?
Have you reset the pcm since you swapped the new plugs and cop's in

 

im at 90,000 miles maintained regularly! i went with the granetelli ones probably should have went back to factory but i wanted to give something else a shot ive checked to make sure it wasnt a bad cop just in cas i had a 1 in a million chance that i took out a bad one and put another bad one in but it seems to be working and ive cleared the code several times to see if it maybe just had to run a drive cycle but it just comes back im running out of options and i think as much as i hate to do it ill have to take it to the dealer and take it up the rear

 

oh and btw hollowed out those cats and did a cel delete

 

im thinking i may have a valve issue i hate to say it but i just cant see it being anything else what stinks is it had a valve job done at 75 when i bought it im wondering if whoever did it did a shotty job

 

oh and i ment to put in there i put the factory motorcraft plugs back in