Not cool. Shouldn't the HF cats hold up regardless? Could this be busting motors from blowback into cylinders smashing valves against pistons?
I'm going to have mine checked for sure.
Exhaust manufactures should be hearing this as most people are doing HF cats with exhaust upgrades and then SC's. If CATS aren't holding up, and most places require emissions test, then it only makes sense that cats are buiilt with better materials to hold up to the heat. Perhaps, real iron instead of melting inexpensive billet aluminum, eh?