Ok so i drive a 2004 A4, about a month ago my stock cat completly failed and was replaced by audi. now a month later and a new stock cat it has failed again. from what ive heard this should never happen, any ideas on whats wrong and causing this, because all the people at audi i have delt with due to this have no clue why it happened they wanted to blame my forge dv, evo intake, and magnaflow exhaust, but droped that very quickly when i asked how they could prove that was the case, any help at all would be great, so i can go deal with the dumbass on monday thanks

 

and when i say fails it gets bright red and barely and exhaust gets out

 

come on any one alittle help?