By-Pass Air Control (BAC) Valve: MPV

BAC valve is mounted to dynamic chamber, near throttle body. Remove BAC valve. Circulate cold water in BAC valve coolant input hose to cool valve. Circulate hot water in BAC valve coolant input hose and ensure air valve operates. Replace BAC valve as necessary.

Fig 1: Identifying BAC Valve (Millenia 2.3L)

Courtesy of MAZDA MOTORS CORP.

Fig 2: Identifying BAC Valve (MPV Shown; Others Similar)

Courtesy of MAZDA MOTORS CORP.