szercer

I want to go with a hooker universal exhaust sys. that runs pretty much straight back from the headers to mufflers with no cats as opposed to the x-type system it has stock with the 1 cat in the middle, is this gonna create plumes of smoke or will it not be that noticeable or is it just a bad idea? Also, the hooker setup only has 2 1/4" pipes, I would have wanted 2.5", is that a very big deal considering it isn't going through a single pipe in the center like stock?

Larry B.

Catalytic converters do not change the VISIBLE exhaust. If you car doesn't smoke now it won't change. I will effect the emissions so if your state requires a smog cert then you cannot remove them. It is also against federal law to remove any emission devices. :D

flood

I put a CAT on mine when I got it. I had to in order to pass emissions testing. I did notice that when I put it on the smell of exhaust went away. I don't think there will be any smoke but the exhaust smell might become noticeable.

Biker

Silvervette is right, if the car isn't smoking now it won't smoke when the catalytic is removed. I replaced my cat with a straight pipe. I love the flange joints used on the '81. I can easily slip the cat back in when I go for state emissions testing.

szercer

thanks for the help, I'm emissions exempt in CO, any thoughts on the pipes size being to small or not? 2.25"

VolVette

2.5" will flow about 19% more, assuming the same velocity. It depends on how much power you have whether you'll need the extra flow but if you're in the 250HP range, 2.25 should suffice...

Stephen