found this guy who is selling a catback....RS JASMA, i have never heard about this brand, dont know if its good, any info about it??

 

I don't know what the whole RS thing is about, but JASMA is not a brand. JASMA (Japan Automotive Sport Muffler Association) is a certification for street legality in Japan.

The closest thing I can get out of this is that he's selling you an RS-R catback; which I believe are JASMA certified.

 

who....

 

it might also be HKS. I know their header says JASMA on it.