Replace Pre Cat with DP? Will it pass emissions?
 

I've been doing research on 3rd gen RX7's because I plan on purchasing one by early spring.
Will replacing the pre cat with a downpipe cause me to fail emissions (assuming the engine is in good running condition)? I've been reading conflicting articles around the web.
I live in CT and am not sure of what the emissions reqirements are. Anyone in this forum familiar or have had experience with this?

Thanks,
Matt

I know in NJ, you'll pass just fine... just make sure that the car is already warmed up first and stays that way through the test...

I live in California, land of the smog nazis, and I was able to pass our strict smog dyno test with flying colors with a DP and CB on the stock ECU.

Thanks. I've been reading that the pre cat tends to clog fairly easily resulting in engine failure.

Another question, what is the average hp achieved with bolt-on modifications using the twin turbo setup ?

Whats the highest achieved with the twin turbo setup?

These might be very broad questions with infinite answers, but I'm just trying to get a feel of what to expect.

Thanks

Please read the newbie stickie at the top of this forum, along with the accompanying links. There is a ton of great info that will answer all the questions you have.

Don't know what your emissions standards are but here in Texas they put the car on rollers and check emissions at different rpm. My car with downpipe and stock main cat passes easily.

In NJ, they do the same thing as Texas...

It should. since the precat is designed to work at start up. Once the car is warm it's your cat that determines whether you pass or not.

Alright, thank you.
BTW, what cat-back systems are the most popular for the FD?

The best OEM look cat-back is the Racing Beat Dual. Nobody complains about them and they like the reasonable noise levels - it's pretty quiet. That's what I'd get if I had $500 to spend (after I get an aluminum radiator, anti-det mod, replace FPD and hoses, etc)

If you want noise, obnoxious ricey-looking single tip, or really need that 1 extra HP to come from your cat-back, then any other brand will do.

The search feature on this board will do you big favors, Saner-san.