Does anyone have any experience with aftermarket performance exhaust catalysts? Any problems come MOT time with say a 200-cell per sq.in. cat?
Ceramic or metal substrate - anything to choose between them?
Something like this for a 220bhp engine?..



that is a 330 cell ceramic, but a 220cell metal substrate is available.

 

sorry mate,,, dont know anything about them,,,, BTTT

 

Ive got a 100cell cat, passed the mot fine.

Just took it for a blast before to make sure it was nice and hot.