How Much Louder Is A De-Catted Exhaust?

[angusis2fast4u]

I really don't be one of these kids but I can't really get a solid or great answer and i've searched the forums and google.

My mate had an SR20 with a 3inch Cat-back (including cat) including highflow cat. Now he said as soon as he gutted the cat the exhaust started popping and shooting flames, Just by having this exhaust and gutting the cat (as well as being noticably louder post gutting).

I can't imagine a high flow cat causing this much back pressure that all of a sudden it pops and shoots flames? I have an RB20det with the same 3inch Cat back (including high flow cat) Can anyone confirm by just gutting the cat it would actually make That much difference?

[gtr jet]

Yes, it will most likely crackle and shoot flames but it all depends on the tune. Only way to find out is to kill the cat.

[Ben C34]

Not much louder on a turbo car.

[Kinkstaah]

I did this (to test something, I since have got a cat) and the only thing I noticed was a slightly different, more 'tinny' sounding note from the exhaust. The sound difference was negligible, and I don't think it was any 'louder' as opposed to just being slightly, slightly different note.

I noticed no flames and/or popping but I'm on E85 and the tune wasn't set up for that, so it's not like an automatic thing that flames literally explode out the exhaust the second you remove the cat.

I also didn't notice that "noticeable smell" that people refer to all the time with a cat removed - but I was on e85 which has its own noticeable smell to begin with.

[Jordy32]

Might crackle and pop a little bit more, found it a little more raspy on an SR but my RB seems to be a little louder.

My car's cat has been gutted by the previous owner and by god does it smell, if you're behind it for long enough your eyes will start to water too

[Ben C34]

Those that complain about the smell I would be very interested to see what afr's you are running.

[angusis2fast4u]

Thanks guys, just confirming if he was BS'ing me or not hahaha