Hello all got some ? I got a 94 FD3s still running twin turbo on it.Want to know if i change the setup to single turbo will i be able to pass emission? Here in Oregon they only sniff test my tail pipe if not is there a way to get it to pass? This's the only thing that hold me back from going single.

 

My single turbo passes emissions fine in Maryland (which I think uses a stricter test involving putting your car on the rollers).

The key is...

1) reinstall main cat (or high flow cat) for the test.
2) Find a way to provide extra air to the main cat (either via the belt-driven stock pump or an aftermarket corvette air pump)
3) properly tuned fuel map for passing emissions
4) Optional : 15% denatured alcohol in fuel tank

Single turbos WILL pass sniffer tests if you set them up right.

 

so what are these tests done for because i have never heard of them before and here in new zealand we don't have anything like that here.

 

basically, in high populated areas smog builds up... so to keep it down vehicles are required to keep their emissions below certain levels. They vary around the country... some places don't have them.... some do.

Generally, they put your car on rollers (like a dyno) and take it through the gears and measure the exhaust fumes via computer. You pass? You win. You fail? You gotta do it again until you pass..or you don't get to renew your registration.