I just replaced an original Cat on my exhaust. That's what I needed to pass Emmisions testing. I had know ideal till I got it up on the rack that there were two others? After replacing the rear which was the original the performance really improved. Here's my questions. What purpose are the other two and since the rear was clogged are the other two possibly needing replacement? Last question, Since I have 2 years left before the next test is there a complete exhaust option that will increase performance but not be deafening? Thanks!!

 

The car was designed back in the early days of Cat technology, so all three were needed to get the emissions down.

Technology has improved a lot since then, and there are several one cat replacements. Problem is in some areas (like California) you'll fail if you only have one cat, even if the emissions are low enough.

However, if are lucky to live in an area where they don't care how many cats are there as long as you meet the emission standards, then check out: www.rx-7.com www.mazdatrix.com and www.racingbeat.com

 

That's what I was looking for!!! Thanks for the reply!