How many ways to gut a CAT ?

[dest]

Mine has gutted cats and doesnt sound any different apart from a little rasp when first started from cold. It also pulls better too. Tbh you wouldnt be able to tell the difference just from hearing it

[EspenW]

Any decent flowing cat will flow better than a gutted one due to the expansion and contraction of the flow. These friction factors create drag at all rpms and turbulence (and even more drag) at high rpms. If an improvement was felt after gutting a cat, it was likely partially clogged.

[dest]

My cats are fine and passed the mot no problem, the gutted ones are spare.
MRC gut precats on the s/rs4 so gutting them cant be that bad a thing to do!

[gunman]

Paul

Dee's exhausts will de-cat your car by welding in a straight pipe for £40 a cat. I'm thinking of getting them to make up sections so I can remove my cats but refit them each year for MOT.

[S2central.net]

Had a quick look today and of course those CATs also serve as place for mounting points to the chassis so it would need to be a nice tidy job with bypass pipes for a decent fit... In which case I need to wait until I am on the road again to get it done properly on the car. I'll maybe take them off to investigate further.