Just took my S5 TII through Jersey inspection on Saturday and passed. Good for 2 years, but really don't want to go through the hassle of removing/replacing the entire exhaust and the air system.

I was thinking of installing a Random Tech 3" cat in front of the RB Silencer (Turbo back system). From my experiences I haven't noticed any decrease in performance with the additon of a good quality cat, but never tried one before the silencer though. Didn't want to replace the silencer with the cat because it gives the car too much of a droan at highway speeds. 65 and up it's difficult to hear the radio and carry on a conversation.

Anybody have any ideas to the validity of this idea?

 

I don't see why it wouldn't work. Bonez has a presilencer in front of the cat for the T2 exhaust, but I don't think it'd make much difference.