Hey guys i was doing a koer test today on my truck and noticed when the test starts the engine runs very rough. Just was wondering if that is normal?
while doing the test in got a p0476 exhaust pressure control valve range / performance code. tried looking into some other threads on that code but they were kinda dead ends. anyone know what causes this code?
So i was wondering if my ebp butterfly was working properly, i ran the koer test again and got in there to watch the butterfly close. the actuator rod does move and it looks like its connected to the butterfly but i don't hear anything different other than the engine rpms go up. from other threads i have read, they said it was a VERY noticable when the butterfly closes, ive heard some people say it sounds like a loud jet engine. I don't hear anything of the sort. Is it possible that the butterfly is broke some how and not closing? i can see it move but maybe its broke internaly? It finally got into the 30's here in florida and i noticed that the truck does raise the rpms in order to warm up but the rpms surge up and down. not sure if that has anything to do with it or not. thanks for any input guys

 

I have read that the arm needs adjusting in some circumstances, and others that it needs to be cleaned or repaired.

Probably not much help, but someone with vast knowledge will pop in shortly. I am in North Florida and my arm needed adjusting when that happened to us. Now we are back to the jet motor on these cooler mornings.

 

great info, thanks whitey. do you know how to adjust the arm? can it be done with turbo and everything intact?

 

No, it cannot I've attached the installation and adjustment procedure.

 

Just for clarity, the jet sound is more noticeable listening to the exhaust pipe at the rear. It may not be as noticeable if you have your head under the hood of a cold 7.3 watching the actuator.

 

Thanks John, looks like i will have extra work when i rebuild the turbo.

 

i did check at the exhaust while the koer test was going and notta. maybe a very faint jet engine sound but nothing like what others have claimed.

 

do you guys think it is probably the butterfly throwing the code or something else?

 

Let me say this about the EBPV butterfly system.

I rebuilt my EBPV piston on the bench. I didn't read the adjustment procedures ahead and time and was unprepared and impatient so I "guessed" by making it the same length as the original.

*Maybe* that is okay? Maybe not?

But now that EBPV flapper is on my list of suspects, I am kicking myself because I do not KNOW it is correct and thus cannot rule it out.

Be wiser than I. Read ahead to have the spring and such handy and take your time to do it right.

Those are my words of wisdom today

 

are you referring to using the weight measurement (looks like a fish scale) to adjust the actuator rod? a fish scale might actually work now that i think of it. i have felt like the truck has some sort of exhaust restriction since i bought it. feels like the engine is doing a lot more work than what its output is. i guess it could only be the ebpv or a backed up muffler. both are on the replacement/ rebuild list.

 

Yep