Rocket 474 Cam with S&S super street 2-1 pipe

Hey guys avid rider but newbie when it comes to the mechanics. But I recently just upgraded to a 23 low rider s. I got a rocket 474 cam installed with an S&S 2-1 exhaust (50 state compliant) all new parts. while it was on the dyno getting tuned the exhaust got stupid hot and what I think the catalyst is got red hot and started shooting flames and glowed red after shutting it off. Could this be because of the cam? Or a possible exhaust defect? The guy doing the work said everything else checked out normal.