AIV question

[huevos]

ok so the AIV valve on the exahaust manifold lets air in the exhaust at idle to lean out the emision, correct? So I want this fella working if I want the car to pass emissions. It seems like most people remove the AIV when doing the SR swap, Why? I have heard it doesn't affect performance at all, so why remove it? does it get in the way or something?

[AKADriver]

The SR's AIV tube hits the steering shaft in LHD cars.

The purpose of the AIV is to inject extra air before the cat to light off the cat more quickly and keep it running hot. If you drive around for a while, really romp on it a few times, before going in for the smog test, it should be able to pass without one... especially with the turbo heat in the exhaust stream.

If you're really worried, you could do like Nissan did with the S14, and run a tuned ECU with a lean idle program.

[huevos]

thank you thank you