IS350SWFL

Before i got my 2015 IS350 F Sport, i had a g37 coupe with resonated high flow cats. They were by far the best bang for your buck mod...much better acceleration, eliminated any lag, and gave the exhaust a deeper sound. In terms of performance, HFCs were much better than a catback or axleback exhaust. I've looked around, but havent seem any mention of HFCs for the IS. Are they not available, or are most people just more interested in sound and go with exhaust systems?

forum429

The cats on the IS are on the headers.
The only way you can replace the cats is to replace the headers.

NVMarkus

iTrader: (2)

if you still have both sets of Cats on your car you could get high flow from PPE and keep the ones on the headers