So I've been lurking and reading all sorts of posts here. This past weekend I finally got around to a few repairs. I wanted to thank everyone for all the good info out there.

I put in a test pipe-my car was making some sounds that I suspected was something loose in the cat, turns out it was the entire honeycomb loose in the cat! That install went pretty well except all of the bolts supplied were wrong. But that's expected from what I hear.

Then I replaced the diverter valve with the 15 psi max 710N, that was great except the little 90 degree hard plastic piece above it was so brittle it just shattered. I found a 90 degree copper pipe elbow worked perfectly.

Also replaced the slightly leaking coolant temp flange- that was a PITA!

All in all went pretty well and I really appreciate all the good info on here.

Also got a belly pan from ECS as my car didn't have one when I bought it. I'll see how the fuel economy is with the test pipe and then put on the belly pan and see if it changes like I hear so much debate over!

2003 audi a4 B6 Quattro 1.8T 5 speed. In the fastest color- Silver.