Free Flowing Cats

[robgt]

Has anyone fitted them. Apparently my car has 6 cats, when removed and replaced with 2 much smaller ones I can expect even quicker throttle response with an albeit small top end power gain. I would anticipate an obvious weight reduction plus a lot more V8 music. Would the warranty be blown. Thanks in advance.

[robgt]

Is the idea to just change two cats and if so at what cost? What gains would it achieve. Same applies to the exhaust manifolds. I'm sure doing the latter would mean bye bye to my warranty.