questions about high flow cats

[kirby26]

hey i just had a few questions about high flow cats. i was told in order to put one on i was gona have to replace all of the o2 sensors, is this true? if so are there special after market o2 sensors you have to get? also how much of a difference does it make in sound and performance?

[turbospotter]

meh get a o2 stimulator for 40-50 bucks. Removing the cat/ getting a high flow only gives you top end sacrificing some low end.

[maximaman]

I didntnotice much of adifference after i put the hi flow cat in. I got short ram too so the difference off the line was unnoticeable. A little throatier sound mixed with intake. Once again... The sound was a pleasantly barely noticable gain... Along with the h.p. Very minor, almost not worth the hastle.

[kirby26]

did you have to replace your o2 sensors? the guy who is doing my exhaust says that i am going to have to replace them, but the place that is selling the cat says that i won't have to. i only ask cause i have to replace the old cat cause there's a leak in it. so instead of buying a stock one i was just going to replace it with the high flow. but those o2 sensors are $120 ea. i also just purchased an after market exhaust so i was going to have him put it on when he did the exhaust. i don't want to run just a straight pipes cause i still want to pass emissions. another thing, there are three cats on that car did you replace them all with the high flow, or just one?

[kirby26]

what does an o2 stimulator do? and is there anything else that i have to do, or do i just put it on and it just works?

[maximaman]

I think ur mechanic is feeding u b.s. The guys who did mine just drilled a hole in the pipe right after the cat and plugged in the old sensor. No problems

[kirby26]

good to know. im definately not going to that guy then. thanx dude. probly just gona grab one, i have to replace it anyway.