IS IT BETTER TO KEEP THE EMISSIONS ON THE CAR OR GET RID OF IT WHEN I GET THE EXAHUST DONE

 

The short answer is: Do what your local/state laws allow you to do. There seems to be a great deal of variance between states on how often emissions testing is done, and what the technicians are supposed to look for, however, so it pays to be informed. But, as always, this question deserves a lot of discussion, so I'll try to start it with my "two cents." It best to look at all of the major systems of emission control in our cars and see what (1) each costs in terms of horsepower to run, (2) what benefits (if any) one might receive from running each one, (3) what "packaging" advantages one might gain by ditching one or more of the devices in question. EGR probably doesn't cost too much in terms of power to run, and it might confer a slight benefit in that it allows us to run lower octane fuel if we choose. AIR injection does cost a few horses to run because of the pump, can be expensive to repair (have you ever priced a diverter valve for a tuned port engine? It's expensive), and the exhaust manifold tubes can be difficult to route plug wires around. The catalytic converter can be restrictive, but you can buy a new one from the aftermarket that chokes off very little horsepower. The PCV system really doesn't cost much of anything to run, and in another discussion board (for a different brand of car) I read that it can keep evaporative fumes out of the passenger compartment by rerouting them into the intake manifold. Please keep this in mind. The hotter your exhaust is, the worse your oxides of nitrogen emissions will be (NOX). The cooler it is, the more carbon monoxide you will see at your tailpipe (CO). I hope that this response doesn't confuse you, I just figure that people should have as much of the big picture as possible before junking emissions parts. The costs for non-compliance are just too high to not consider this stuff in advance. Good luck.

 

What "emission" items were you considering "getting rid of" when replacing the exhaust? If you install a complete exhaust system, the only emissions component involved would be the cat converter. You can install a high-flow cat and forget about power loss from it.