Gutting a catalytic converter

I just ordered the OBX Type H cat back exhaust, and was thinking of gutting my cat while I had the exhaust apart. What is involved in doing so and how do I go about doing it?

To gut your cat you need to break out all the honeycomb looking stuff on the inside. I did it to my old cat and I didn’t really feel a difference in power. Besides being more harmful to the environment, it stinks like hell. I couldn’t even breathe every time I came to a stop with my windows down. My opinion, DON’T DO IT. :down:

Originally posted by jdm91integ
DON’T DO IT. :down:


My children’s children will thank you.


there is a post that states why you shouldn’t do that…it creates some sort of swirling in the empty chamber and it dosent flow as it should.- something like that but i know its not good either way you look at it.

yes, a hollowed out cat on our 4cylinders creates a lot of turbulence and shifts the powerband way higher than most stock LS’s an even GSR’s. not worth it IMO, a test pipe would be better because it doesnt create as much turbulence


do not hollow it out, I did it and it was a $400 dollar mistake, come emissions time I had to buy a new one, plus when it was on, I was pulled by the cops over many times because it stank real bad behind me. even my friends didnt want to follow my car it suffocates anyone behind you, and if the winds blowingthe wrong way, it suffocates you in the car, trust me, dont hollow it out. but if you do heres how to do it, take a long thick metal spike and a mini sledge hammer and pound the shit out of it, the honey comb will fall out in bits, then get some needle nose pyers to pull out the metal mesh around the inside walls. Have fun:)

dont do, i regret it. now if u dont wanna listen to us, ill gladly tkae your good one and u can have my gutted one.

ok hers why u dont wanna do a normal pipe the flow is constant so no turbulence.


the air just goes str8t thru. no problems
but when u expand in one section, it has to fill that expaned section before it continues

… ****** …
******… ****** …
*************** …
it wont just go str8t thru b/c our 4 cylinders dont have enuff power to push it thru.

so the car is gonna feel like a golf kart cuz u loose torque(reversion-inert gases which cant be ignited are sucked back into cylinders)

and not to mention the smell,killing the environment and my reason i want mine back, my car sound like SHIT

EDIT-my illustrations look like crap,but the stars mean nothing,the periods are the exhaust pipe. just think of it like this, say u have a river (exhaust flow) and between the river there is a lake. well the water has to fill up the lake before it continues down the river. when it fills in the lake it greatly slows the flow

to sum up what everyone is saying and hopefully you have decided on the right way:

  1. leave the stock cat alone.
  2. if you want a more flow, get a high flow cat.
  3. gutting results in poor performance due to improper and turbulant exhaust flow.
  4. your car will stink
  5. just not worth it

and most importantly
6. everyone will thank you for not gutting.