Air Management System Functional Test
- Check diverter valve operation; valve should not pump air to air cleaner hose at part throttle, but should on quick deceleration or any time vacuum signal drops below 3 in. Hg.
- To check select valve operation, start engine and run at fast idle. Pulsation should be felt in hose to exhaust ports until system goes to closed loop, then it should switch to catalytic converter hose.