Unit inspection

Switch the ignition ON (engine off).
Connect the M-MDS to the DLC-2.
Access the PID/DATA monitor item EXHPRESS_DIF using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .)
When the ignition is switched ON, verify the value of the PID item EXHPRESS_DIF.
- If the monitoring value is within the range of +/- 2 kPa, go to the next step.
- If the monitoring value is outside of the range of +/- 2 kPa, replace exhaust gas pressure sensor No. 2. (See EXHAUST GAS PRESSURE SENSOR REMOVAL/INSTALLATION .)
Disconnect the air hose at the position shown in the figure.

Courtesy of MAZDA MOTORS CORP.
Install the Mityvac to the position shown in the figure.

Courtesy of MAZDA MOTORS CORP.
Verify the Mityvac gauge value and PID item EXHPRESS_DIF when pressure is applied to exhaust gas pressure sensor No. 2.
- If the difference between the Mityvac gauge value and the value of the PID item EXHPRESS_DIF is within the range of +/-3.5 kPa, go to the next step.
- If the difference between the Mityvac gauge value and the value of the PID item EXHPRESS_DIF is outside of the range of +/-3.5 kPa, replace exhaust gas pressure sensor No. 2. (See EXHAUST GAS PRESSURE SENSOR REMOVAL/INSTALLATION .)
Install the Mityvac to the position shown in the figure.

Courtesy of MAZDA MOTORS CORP.
Verify the value of the PID item EXHPRESS_DIF when 110 kPa of pressure is applied to exhaust gas pressure sensor No. 2.
- If the value of the PID item EXHPRESS_DIF is0 kPa or more, replace exhaust gas pressure sensor No. 2. (See EXHAUST GAS PRESSURE SENSOR REMOVAL/INSTALLATION .)