O/R Pipes and Emissions
 

What exactly do people with Off Road pipes do about emissions? Are these usually not DD cars? Or do you put cats back in every two years? What exactly are the benefits of O/R pipes anyway?

Most people just put the stock H back on when it comes time to smog. The benefit is a louder more aggressive sounding exhaust. Performance gains are up in the air. I actually lost low end power when I had an o/r prochamber.

Im glad im from Maryland, We do not have Emission testing unless you sell the car! So I can run any pipe I wan't cops don't nail you usually unless they can smell is from the car pouring out which in that case of being pulled over for speeding shut the car off! And be easy on the pedal here in MD and we are good to go! I was thinkings of doing an off road pro chamber not now Thanks GMAN im glad I found that out!

The loss of power wasn't too bad. I dynoed my car on the same dyno, but at different times with the stock catted H, o/r prochamber and prochamber w/hi-flows. Weather was not really an issue, the dyno is already SAE corrected. Here are the numbers:
Stock catted H-297RWHP/309RWTQ
O/R Prochamber 302/RWHP/305RWTQ
Prochamber w/hi-flows 305RWHP/312RWTQ

As far as sound, prochamber/hi-flows sound the best.

That must be county specific than as I used to live in Montgomery County and we had emissions tests every two years. We only had safety inspections once though (either when moving into the state or when buying the vehicle).

So hi flow cats make the most power, interesting. How is the sound with the hi flows vs the stock cats?

The hi-flows will make the car louder, but not too much louder.

no hi flow will not make more power...his results are a fluke if anything.

Do you mean compared to the stock or the o/r pipe? I could feel a little loss of power below 2000-2500 RPMS with the O/R prochamber.