ok here's my problem. idk if hollowing out my catalytic converter would help to gain horsepower or if it would cause a decrease in HP and make my internals fuck up from bad readings and what not. i've searched for high flow cats. but they dont make any for my year...its an 02 miata. i was also considering a straight pipe, but if i got pulled over i wanted it to at least look like i have a functional cat. i hope you guys know where im going with this.

any help would be greatly appreciated.
-mierski

 

2002, That's an OBDII car right? Don't they have an O2 sensor AFTER the cat as well as before?

Dunno if that will make the ECU freak out and kill engine performance trying to meet emission standards.

You could always try a straight pipe. I can't remember the last time i heard of a cop checking for a cat.

 

^ yeah if cops pulled over people and checked for cats then I'd be serving a 4 year sentense by now. Try a straight pipe. I don't know how much power you'll gain since you're NA, but you may pick up some low end power.

 

Low end?! i got gobs of high end when i took the cats off my RX7. Maybe because they were 18 years old

 

Well I was talking about an NA motor. Taking off the cats on a turbo car turns into a whole new car.

 

GXL's are N/A

 

I know that, just didn't realize what car you drove unitl now.

 

Take the cat off,we dont have inspections.. but if you ever need to take yoru car to a shop for exhast repairs,and you dont knwo someone on the inside.. they wont do it..

I dont belive in hollowing out cats.. just straight pipe it.. and I have never seen a 02 after the cat..

 

thanks for the help guys but i have one more question, what do i do about the o2 sensors....do i thread the straight pipe and plug it back into the pipe or what, or should i disconnect them altogether....

 

? The cat should have a separate pipe that can come off. they're made to be replaceable