I recently aquired a test pipe to use in place of my catalytic convertor. Is anyone using this pipe? Did you feel any gains? From what I remember they ususally do not net much HP if any at all on NA cars, but help big time with boosted cars. How does the vehicle smell without a cat and with aftermarket y pipe? Is it much louder as well?

 

I have a y pipe and test pipe, there isn't any noticeable noise gain. I noticed some performance gain at WOT. One negative is that the car now smells like a lawnmower and when emissions rolls around, you will not pass.

 

Same here, I didnt notice any gain at all. I did notice the smell, it has a real strong exhaust smell now.
If my previous cat hadnt of failed, i wouldnt have gone this route.

 

just dont do it..........

 

No gains, only with boost. It is a lot louder with test pipe, and it will smell like isht.
Not to mention the chances of getting caught.

 

all are true, i have the custommaxima test pipe and f-in hate it. ruins ur sound and really really smells. my warpspeed cat convertor came in and just waitin for installment