As has been mentioned already, quality of the cat is extremely important, both for performance, but also what isn't mentioned much is longevity. The best catalytic converters are made by HJS and GESI. We're big fans of the AMS downpipe; it uses an EPA-certified GESI cat with a brand new substrate wash formulated for new car emission requirements. It is not an off-the-shelf GESI cat.
Sponsored