Bypass Air Control (BAC) Valve (Millenia S 2.3L)

WARNING: This page is about a different car, the 1995 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.

Start engine. Disconnect air hose from BAC valve at port "A". See Fig 1 . When engine is cold, air (vacuum) should pass through valve. When engine is warm, air should NOT pass through valve. Replace valve as necessary.

Fig 1: Identifying BAC Valve (Millenia S 2.3L)

Courtesy of MAZDA MOTORS CORP.