Emissions Question

[NY2000SVT]

When it comes to aftermarket exhausts, when and how are emissions affected? I'm guessing with just a catback aftermarket exhaust your emissions wont change, the only legal issue is loud exhaust. What happens when you take the cat out and go to a straight pipe? If you remove the cat, your car will fail the emissions inspection won't it? I live in NY and they're pretty strict with the laws on that here. I think they plug into the ecu to check the emissions now though rather than the hose over the exhaust pipe. Maybe you guys just keep your old exhaust system and when you need to pass inspection you just bolt it back on?

 

[Tony2005]

The "plug in test" also involves a visual inspection. So they will have to "miss" the missing main catalytic converter to pass you. In addition, if you have headers (or gutted) precats, you need mileliminators for Bank 1 and Bank 2 Lower O2 sensors or the CEL will light up for P0420 and P0430.

Mileliminators in M&M how to.
http://www.contour.org/ceg-vb/showthread.php?p=47730#post47730

 

[Big Jim]

The rule of thumb on exhaust systems and emissions is that you need to leave everything stock from the engine to the back of the cat, or if it has multiple cats, to the back of the one furthest downstream.

Anything after that is fair game unless you have noise limitation concerns.