I have a 1986 RX7 N/A and bout a month ago installed a stock cat converter so that it could "pass" smog. but just recently i started hearing kind of like rattling under the shifter where the cat goes. i dont know if the cat is blow or what but it gets annoying everytime i take off or stopping at a light because everyone looks at me.

i could really use the help here so that i can go buy a better one and new tips because the "one" that i have is really loud. yes i only have one exhaust pipe with tip and its very annoying to hear it over the engine.

also should i get a stright pipe instead of get the cat and what kind of tips should i get? i know there is racing beat but thats a little to expensive for me right now because graduation is comming up and i need to pay some fees.

so in all i really need help with the rattling and if i should get a new cat or stright pipe and what kind of tips

 

Could be a blown cat. I'd also check the heat shield around the exhaust manifold or whatever Mazda calls it...always forget. I've seen a car where the heat shield had lost a bolt or two and rattled like an beyatch.

 

^This just happened to me, actually. The thin metal on the scrape shield (I guess that's what it's for, mine always scrapes speedbumps) had snapped and one side was flapping. I did the ghetto fix of wrapping some piano wire around the broken corner and the bolt head and it's good now.

 

do you have any broken exhaust hangers?

mine dry rotted and the exhaust pipes noise until i put new ones.

 

Might wanna remove your shifter and check for broken shims or bushings.