where is the air switch relief valve on an air pump?

Answer 1

Year, make and model? It's usually bolted to the pump itself or it's attached to the air injection hoses running from the pump to the exhaust...also called a deceleration valve but every manufacturer has it's own name for it. It releases excess air on deceleration. A dealer parts dept for your car can show you a picture of it or what a new one looks like so you can find it on the motor.