What is a secondary air injection?

Answer by  Jessie124 (1885)

It has to do with a car's emissions. It's where fresh air is injected into the exhaust, which increases the combustion of exhaust gases. It was introduced in the 60's.

Answer by  Irvarvlin (17)

This is a technique that injects fresh air into the exhaust products. It helps to ensure more complete combustion occurs.