Mazda 626

1991-1998 of release

Repair and car operation

Mazda 626

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 4. Heating and ventilation
+ 5. Fuel system
- 6. Exhaust system
   + 6.1. Exhaust system
   - 6.2. Systems of decrease in toxicity of exhausts and management of operation of the engine
      6.2.1. Introduction
      6.2.2. System of self-diagnostics and malfunction codes
      6.2.3. Central control unit
      6.2.4. Sensor of provision of a butterfly valve
      6.2.5. Sensor of a stream of air
      6.2.6. The sensor of temperature of arriving air
      6.2.7. The sensor of temperature of cooling liquid
      6.2.8. Sensor of provision of a cranked shaft
      6.2.9. Sensor of provision of a camshaft
      6.2.10. Switch of system of hydrostrengthening of a steering
      6.2.11. Oxygen sensor
      6.2.12. Sensor of detonation combustion of fuel
      6.2.13. Sensor of speed
      6.2.14. Air valve
      6.2.15. System of additional supply of air on low turns
      6.2.16. System of ventilation of a case
      6.2.17. System of a retsirkulyatsiya of exhaust gases
      6.2.18. Collecting system паров fuels
      6.2.19. Switch of fires of a stoplight
      6.2.20. Catalytic converter
+ 7. Transmissions
+ 8. Coupling and semi-axes
+ 9. Brake system
+ 10. Running gear
+ 11. Body
+ 12. Electric equipment
+ 13. Electroschemes
+ 14. Good advice

6.2.11. Oxygen sensor


The oxygen sensor checks the content of oxygen in exhaust gases. On the basis of information from the oxygen sensor the electronic control unit regulates structure of a fuel mix.


1. For check of the primary sensor (located in front of the catalytic converter) connect plusovy щуп the voltmeter to the alarm plug of the sensor, and minus щуп – to the weights plug.
2. Start the engine and check, that tension between plugs made 0,1–0,2 Volts, while the engine cold (the engine works in an open mode). Approximately in two minutes the engine and the oxygen sensor should get warm and tension should start to fluctuate between 0,1–0,9 Volts (the electronic control unit passed to the closed operating mode).
3. Check, that resistance of a heating element of the sensor made 10–40 Ohm. Check tension giving on a heating element.
4. Replace the oxygen sensor if it is faulty.


1. Disconnect the socket of connection of the sensor and accurately unscrew the sensor.
2. Grease a carving of the new sensor before installation by anticorrosive structure. Installation is carried out upside-down removals.