Been a member for a while, mostly just a reader

Not sure if this is the correct place to ask for help but here goes

Waited till warranty was up at 100k miles. Took my truck to a local recommended shop (I'm kinda out in the boonies, so I dont have much selection, but this shop came recommended by a fair number) and spoke with them about doing the following. I wanted to get rid of the DEF requirement (I've had 4 tank/heater unites replaced under warrenty) also wanted to better my mileage, 13 mpg stinks. As well wanted to do anything I could to help the longevity and health.
The shop recommended
H&S Tuner Install
S&B intake install
DPF delete
EGR delete

Shop seemed very competent and knew what they were talking about, so i pulled the trigger.

Allow me to preface this with this statement. Prior to doing this I had no pre existing issues.

Well all the work is done but now I have this exhaust thumping sound at idle, and only at idle, coming from the tail pipe. Almost kinda like what an old school glass pack sound like at idle. Now the mech isolated it to certain cylinder by shutting off the injector via scan tool, noise goes away, but an obvious mis. Turn it back on miss goes away but the thumping sound comes back, but it's only at idle.Rev the engine it goes away, take the truck for a drive, it goes away, come to a stop and it slowly comes back. Every now and then at idle the sound goes away but it correlates with what I was told was the turbo variable stators adjusting.

Did a compression check and it's good at 360.

Now I'm being told by the same shop I now need a valve job done on the cylinder, that the sound "could" be a result of exhaust valve pitting and not seating well (but yet the compression check comes back good) well we all know what that means.

I had the shop finish up the work that was done and I would get back with them and took my truck home. Now it runs great and I can tell a noticeable difference in performance, and again, no exhaust thumping noise, only at idle.

Any thoughts on this guy's?

ALSO what would be a fair price on all the work I had done ?
H&S Tuner Install
S&B intake install
DPF delete
EGR delete

Thank you in advance

 

the thumping is popular on 6.4's and on 6.4's the root cuase is usally rocker arms, or bent push rods, or cam lobe wear, or lifter problem.

BUT, the 6.7 has some design enhancements the reduce the possibility of rocker arm tip problems, lifter problems.