Berk HFC, Loose internal catalyst element.
 

Hello fellow Z34 enthusiasts.

I have an observation to make. I recently had to seal an exhaust leak where the HFC connects to the factory header/manifold. When I was moving the HCF unit to my work area I felt the internal catalyst element moving around. It is loose and not attached to the walls of the Cat pipe. I am not worried about it, but do any of you have a similar findings when working with HFCs over a long period of time? For me I have had the HFCs about fours years. The Berk gaskets went to crap. I ended up replacing them with the Z1 flat metal gaskets. They do work great for this need.

What are your experiences?

Just curious.

Out of curiosity, what kind of mods do you have and have you had the car turned after they were all installed? I've heard that a bad air fuel ratio can cause issues with cats.

i have the same finding with the berk HFC... the first set was on the car for 5 years and the second set for 2 years both of the internals were loose and moving around.. fro what my tuner said its common on HFC

Mods
 

I have the full intake and exhaust from AAM (S-Line/R-Line), Berk HFCs. Just to get more HP out of the Z meant a Dyno tune for me. With all this I get more HP (321 wheel, assuming 85% efficient and 391 at the flywheel) and better throttle response.