So i have purchased an ARK Grip exhaust some time ago for my IS300 2018, and when i did they did not have Ark cats available to purchase and install, so i went ahead without them. Now im wondering with the D3 tune, would having these would make a difference in performance or is this something i should wait until a supercharger kit is made? Thanks in advance!

 

I’d think anyone who would actually go through the expense of buying and installing a SC kit would probably do all the other performance mods.

 

Your better without them.