I bought a high flow cat today from ebay. It was cheap so I said what the hell. My question is. If I install it, will it affect my stock cat back exhaust? As in, do I need to worry about anything?

 

nopeeeeeeeeeee

 

the only thing you need to worry about is emissions. if you have them in your area you will fail. the reason is the high flow cat you but is most likely a test pipe/straight pipe. they sell for cheap because they are not actual cats. there are a few high flow cats on ebay but they typically for over 100. alot of the so called high flow cats are just straight pipes.

 

First, do what sloppymax said and make sure it's actually a cat and not a straight pipe. If it IS a cat, then you should be fine for emissions, but you might want to keep your stock cat if nothing's wrong with it. A cheap "high flow cat" (if it really is a cat) might actually be more restrictive than the one Nissan put on the car from the factory.

 

How will it be more restrictive?

 

I'm not saying that it WILL be more restrictive, I'm just saying that lots of cheap "high flow cats" are either simple straight pipes (not even a cat), or if they are cats, they're sometimes more restrictive than the stock cat (just because of bad design).

 

Post pics of the thing, both the outside of it and the inside of it if you can.

 

i have a no-cat design and to tell you the truth, it made no difference at all