I know its very illegal in all, but I guy I know that has an MP3 took his off....from what he told me its simple and slides off after removing bolts and all....He said he got it dynoed and gained nearly 8HP in 5th gear! He also says he has yet to notice any problems and has not seen any lights come on. So has anybody else done it? Im going to try and remove mine Friday morning, ill be sure to say how it went. Peace!

 

How about just removing the 2nd cat, the first cat has in line sensors before and after. The 2nd cat has no sensors in the way. I removed the second cat and it feels slightly better.

Only thing with the 2nd cat is that you need to have a muffler shop take care of it.
________
E-CIGARETTES

 

First of all, this mod WILL light up the "Check Engine" light. If your friend's car hasn't done this yet, it will; it's only a matter of time.

Second, your car will fail the visual emissions inspection with the CEL lit, and it will probably also fail the tailpipe-sniffer emissions test (which you have to get in Harris County and the surrounding counties). The State of Texas has recently enacted new inspection regulations making it impossible to get your car re-tested in an adjacent county without the sniffer unless you have solid proof of residency there.

Third, I assume that your friend hollowed out his existing cat or cut it up to finish his exhaust system. (It's very large and has non-standard flanges on it, so you can't just unbolt it and replace it with a piece of regular exhaust pipe.) It is illegal to sell used catalytic converters in Texas, so you will have to shell out $600+ for a new converter when (not if) your hacked-up stock converter fails state inspection. The cat's funny shape also makes it impossible to replace it with a generic aftermarket converter. You MUST use a Mazda OEM replacement.

In short: BAD, BAD idea. Better idea: buy a real long-tube header, add a relocated aftermarket converter and relocate the O2 sensors (read the FAQ), and carefully store all the stock parts undamaged in case you need to reinstall them to sell the car.

 

I know its not a very good idea to do this...BUT...i just cant freakin wait for some decent racing headers to come out. All I hear is HP Racing this HP Racing that....but no header! As soon as theres proof that there being shipped im gettin one. Anywayz....I am thinking twice about it, but im still not sure....but what im sure of is that im removing the 2nd cat...i met another P5 driver around where I work and he removed his at some shop....and he said he'd take me to the place.....I'm just being greedy and want both cats off thats all. Thanks for the info though