Can anyone shed some light on this, it has me baffled..

brand new Di Filippo 3" cats, ever since putting them on and starting car the passenger one gets so hot that it glows red roar (drivers one is fine) not blocked as still plenty of pressure coming out that side of exhaust.
Is getting that hot its melted the heat shield underneath the car floor pan.
can see tiny metal shards in the back side of the cat (exhaust side) thinking its buggered?

new engine btw.. have pulled exhaust off and mufflers are not blocked, plugs are getting fuel so dosnt seem to be a fuel issue

car dynoed a couple days ago, ran fine on dyno made good power and torque.. just so confused on this cat .. is it a cat problem?