i put a DC sports 4-1 1piece header on my 93 eg and for some reason the header wont seal up to the cat. i have tried like 3 differnt gaskets and it still leaks i have HKS piping on the car but i dont see how that would affect anything , it makes this hissing rattling sound like it is almost sealed but not all the way eventhough i have checked the bolts countless times , if anyone can help or has had this problem i would really appreciate it

 

take it to a muffler shop and see what they can do.

 

since mine wasnt legal i had the shop weld the cat to a pipe extension from the header