100% Emissions or No Emissions w/ Air pump to Cat
 

I have to pass emissions in my county. There is a sniff test and a check for a cat (under car mirror check). I have started to finish the emissions on my t2 motor and learning the details of how the emissions system works I am less and less inclined to finish it to 100%. It seems the airpump, while providing some functions for anti-afterburn and driveability issues, takes air from the airpump and sends a small portion to the exhaust ports and sends the rest to the cat to aid in the reaction with exhaust gases. There is no EGR on S5 engines, so the only emissions functions are basically this air distribution system.

I have an RB downpipe to a custom cat center section with a RB catback. Will I have lower emissions by putting all the equipment back on and running the system "as Mazda intended"? Or, should I take all the equipment off and run the outlet hose of the airpump to the cat come emissions time? Will I see different results? Has anyone documented this?

From what I remember TitaniumTT say, he passed emissions in CT by only putting a cat on and tuning it out. But, if you're running stock ECU, i'd imagine that pumping fresh air straight to the cat would be beneficial. I don't know though, I'm only theorizing here.

Anyone else got any insight? I'm curious, seeing as I'm looking to move into an area with emissions testing.

-J

Look into the titling laws for the state you will be moving to. You may be able to register the car as a Classic which, in PA at least, does not require emission testing.

Where we are in TN, he has to get it sniffed, with a cat check. Whatever you do under the hood to make it pass is fair game.

Here in TN a classic car must be 25 yrs old, and can ONLY be driven on weekend, or to and from a certified Club gathering.

So that doesn't work either.

Classic or antique? i think your getting it backwards, i thought classic was 1000 miles a year or to work only and antique was club/weekend only?Could be wrong, im also in VA

All I know if VA is one of the strictest states on cars and driving.

It doesn't really matter about classic or antique because this is about the operation of the emissions vs a (at emissions testing) workaround.

Has anyone who has emissions testing had equal results before and after emissions removal with such a setup?

my first rx7 back when I was 16 was a base NA 86, I had one year of emissions to deal with in Ohio, simply with a cat I passed the exhaust check-

my vote is on calli

^^^one of the strictest, not the strictest.