2012IS250

What are some good brands and their prices for high flow cats? I did some quick searching and only found magna flow to be popular but I'm pretty sure there are other good ones out there. Do aftermarket cats also have backfire as well? thanks!

RMMGS4

iTrader: (5)

Do you think there is a performance gain in doing this??

2012IS250

Honestly I did some searching around and so far I've read that it improves fuel economy and squeezes out a few horsepower but idk if that applies to the IS.

RMMGS4

iTrader: (5)

After having no cats on the Wife's IS300 for the first 5 years, we put it back on once smog time came and the bottom end torque was notably better. Never removed them after that. I'd value torque at the bottom end more so than HP at the top end myself.

maxx430

not sure if you can buy just any cat. i thought CA passed a law that requires the cat to have a serial number or something.