can you hollow out a cat without messing up your computer

[StreetDemon3.8]

I've put a flowmaster dual exhaust system on my car and im curious if you can hollow out the cat converter i know of a place that will do that where all that is left is the shell. im wondering if that would give me a better sound and more performance without messing up my computer or setting off the engine light

[SixBanger]

Not sure about the computer but there is a good chance your service engine light will come on.

[speedy-v6-camaro]

Someone said theirs didn't go off when they hollowed out the cat....but its likely yours will without a 02 sim.

[camaro_speedemon]

If you hollow out or remove your cat and you don't install an O2 sim, your SES light will come on, and you're computer will put your car in limp mode and you will loose performance. IMO If you're going to hollow out your cat, just get another pipe. The resistance you get rid of when you hollow it out is negated by the turbulance created by the shape of the hollowed out cat.

[Pewter99Camaro]

I hollowed out my cat and the SES light won't go away until I get an O2 sim, but I just keep clearing out the code.

[xjarayax]

I'm running an open forward sweeping turbo y pipe, but I still have the cat and the catback exhaust mounted (but not connected). No problems with SES lights after a week.

[95 3.4 Firebird22hp]

Tomorow I will be taking my cat off will my SES light be coming onif I even have a SES light??