DRE6906

What do you think would be best way on hollowing the cat for the 2 step and still keep that power without loosing any or would a high flow cat work with the 2 step?

Dave87

Well in my opinion, I would think performancew wise you might get a bit more if not the same performance with a gutted cat as you would with a high flow cat. If you have the money buy a highflow cat and gut your car cat, if you haven't already, and take it to a dyno shop and compare your numbers. In addition, if you have to do admissions your best bet is to buy a highflow cat that way you don't have to keep getting underneath your car and switching out parts. That's a pain in the butt trust me. But ultimately in the end it is soley up to you and what you feel is best because it's your car. We can only merely suggest what to do.

BrandonR

If your running street, high flow cat. If your running track only, test pipe. -Later, BR

MR.johnson

2step has nothing to do with a hollow cat or highflow cat. run a test pipe if you dont want your cat.

NotAJDMFanBoy

Get a test pipe. Don't hollow your cat, you can get like $50 or more for it if you scrap it, but they'll give you like $10 for the loose media. And the test pipe will flow better than a gutted cat.

DRE6906

Oh ok thanks and my concern was blowin my cat cause I was told if I 2 step my car the fire that's comin from the engine would mess up the cat

Libertariat

track or street there's no real gain from the difference between a high flow cat and a test pipe.

rhymeshark916

Test pipe will give you headaches due to exhaust fumes. Use a cat.

MR.johnson

so your tell me i should run a 4" cat?

NotAJDMFanBoy

A test pipe is cheaper than a hi flow cat. Sorry, I'd rather spend $40 on a test pipe than over $100 on something that won't flow as well.

And I drove with a test pipe for about a year and no headaches. As long as you don't have exhaust leaks, you won't get exhaust in the car.

EJeff8

Wtf? There's barely a difference in flow and the Cat lets me live a longer life with cleaner air. I've already commented on this type of thread once, I'll just copy and paste.

To not run a cat, regardless of emissions or not is illegal in the U.S.A. If a cop has reason to look under your car and not see your cat, you will be **** deep in car trouble. Don't take it to a muffler shop if you aren't like good *** friends with the owner because they won't touch it, it's illegal for them to mod a car against car regulations obviously.

A cat hold a little bit of pressure to the exhaust system but not much really. It is of course more for emissions but there will be a sound change, might not be a large change either though. Going with a straight pipe will give you more low end power where as running a hi flow cat will push some of that more to the high end. Also depends if you run a 4-2-1 header or 4-1. You'll also need to spend money on a CEL eliminator to fix the CEL issue with the o2. Really, I don't see much benefit. Much easier to just leave it because UNLESS YOU'RE BOOSTING, you'll see extremely minimal gains, sound change, wasted money and potential legal issues, all on a D series.

*But you can also buy straight pipes that look like cat's but just go straight through. Still, not worth it.

Red_Army

^^thats because its a federal law. messing with any emissions oriented part is illegal.

and if your paying more then 10 bucks on a test pipe your wasting money.

DRE6906

I have a high flow cat in my car now I got a b16a2 in my 95 hatch I just wanted to chip my ecu to 2step cause I don't wanna blow my $150 cat