Beware the average user trying to clean EGR pipe and cooler....

Valvoline Protect and restore has cleaning effect on the piston rings groove. it has some engine flush components that can be use with regular oil change interval 5000 miles ideally.

 

Except, it doesn't work. Not for me. Still burning oil. I've done 5 or 6 changes...

 

Ah.., damn. I have a high hope about that. Probably only works if the cylinder wall is not badly damaged yet.
I have a 2015 made engine and it consume no oil with 7500 miles OCI. It is now just 110k miles. Hopefully, stay that way.
I used 508/509 Longlife IV oil from VW, Ravenol, or Aral/Castrol so far.

 

Exactly what I did when I cleaned the egr cooler. Out of all the tasks involved in replacing the head cylinder gasket in my driveway, removing and reinstalling that egr crap gave me the hardest time. I didn’t even consider reinstalling that stud; as soon as I finally got it out, I found a comfortable spot for it in my junk box.

 

I put the stuff back in but I don't put the distal most inferior bolt back in. And I cut that bracket off

 

I think I will just blast the cooler off with air compressor. It is too much work. I will focus only on swapping the EGR valve, pipes, and Intake with the cleaned one I got from a junkyards. I won't mess around with the cooler if it is not clogged. It is an exhaust, they will get dirty in no time. As long as it does not clogged, I am good.