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Has anybody done this and dose it make a differance. ? Thanks

I think most here have custom exhaust, that would mean getting rid of the primary and/ or secondary cats.


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I was under the impression that my car had a pre cat delete, but the primary ones are still there when I checked last week. The secondary cats can be removed as part of the "Cat back " sports exhaust system that a lot have. They simply add a straight pipe to replace where the secondary cats are located. I am not sure if the car would pass an MOT emissions test with both pairs of Cats removed TBH, so think carefully before removing all of them. Emissions on my car are spot on thankfully !

I have a stainless exhaust with seconary cats removed but thinking instead of replacing the downpipes just hollow them out to help with flow

MRC used to knock out the insides of the primary cats all the time, pumping the power from 740-ish to near 790+hp.

Also, just for clarity, the primary cats are at the top of the downpipes directly off the turbo exhaust housing deep in the engine bay and the secondary cats are the much bigger ones visible underneath the car and where "cat back" exhausts attach to.

Yes the ones you can see under the car ive had removed with new exhaust but theres a possibility my engine might have to come back out again so i was thinking about asking the garage to hollow out the main cats while its out.

If the engines coming out it's easy to do with an air chisel etc but you will need a maptweak to stop the ECU light coming on when you have No Cats.

Ahh so i wouldnt be able to drive it once they have been removed. I was hoing that it would of been ok untill i had time and money to take it back to mrc