I am helping a buddy with his 05 f150 fx4, 160k miles bought used about 2 months ago. out of the blue it starts missing and he feels a lot of vibration through the body, check engine light comes on.
he went and got codes pulled on it when the check engine light came on.
p0303 and p0012.

we have replaced the #3 COP as it test outside spec at 1 ohm rather then 0.55 ohm. that changed nothing.

we read up a lot (on here mostly) and he paid a shop to change the plugs, they scanned the codes again and got misfires on #3 and #4, and replaced all 8 plugs.

we then tested the VCT solenoid on the passenger side, it was at 2.6 ohms, well outside the 4-14 ohms to be expected, so we replaced both of them (figured the other one might as well be replaced with the miles on the truck).

we have not had a chance to drive again (we are firefighters on duty), but at idle it still seems to be running too rough.

some other thoughts:
i can clearly hear the clicking injectors, but if I unplug them on the passenger side bank it seems to make very little difference to how the engine runs at idle. possibly going to swap injectors from bank to bank.

the rubber hose for the evap emissions system on the passenger side of the intake manifold is dry rotting so badly you can touch it and get covered in black powder.



what would you do next? we will pull codes again when they come back after driving (tomorrow when we can leave work), but i am at wits end.

 

Compression test....

And

Since the truck is out of warranty on the injector letter....change the injectors.....all of them.....

 

is it possible the injectors are failing BUT I can still hear them clicking while plugged in and engine running? I actually have never dealt with a failed fuel injector before.

 

Pull the rails and perform a leak test.....just need to take out the hold down bolts and lift them high enough to get a gap inbetween them and a paper towel....turn the ignition to on, DON'T CRANK THE MOTOR....let the fuel pump prime and watch the fuel injector tips

I missed seeing the p0012

From obdii codes...

 

we have not rechecked codes, but the vct solenoids were out of spec, so I suspect they were allowing excess oil flow to the phasers. hoping the p0012 goes away.
tomorrow i am going to pull the rail on the PS and see if it leaks at all. I wish I had a safe way of firing each injector to make sure it is flowing as well. will probably swap them around to see what happens...

 

will also check resistances as well

 

another interesting note...the external temperature of the catalytic converters is VERY different. driver side external temp of the main cat body is 275 degrees F, while passenger side is 640 degrees.

 

Change those injectors. Not doing so on an 05 5.4 is like driving a ticking time bomb around. Trust me, I know.

 

i am starting to think leaking injector on that side leads to burned catalyst...
clogged cat would cause misfires in various cylinders on that bank...i wish i could cut the cat off right now...

 

A muffler shop can test the cats for blockage without cutting them off.

 

That's a good fast way to determine a problematic converter.

Yea, a bad injector will smoke them pretty quick.
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I definitely wouldn't key the ignition until I fixed that problem. Your taking a big chance with screwing that engine.

 

Injectors are on the way.
Sawzall and welder standing by to remove catalysts, just got to wait for when the guy who CAN weld can do it!

 

btw he drove home today with the new VCT solenoids and it is still missing and running rough, but NO check engine lights!