Attention! All work on the exhaust system must be performed only on a cold engine, due to the risk of getting burned.
Control over compliance with exhaust gas toxicity standards is ensured by installing regulating oxygen concentration sensors (5 and 6, see Fig. 3.29) in the exhaust gas and oxygen concentration monitoring sensors (9 and 13) in the exhaust gas.
Oxygen concentration sensors are installed in the exhaust manifold before the neutralizer. Monitoring oxygen concentration sensors are installed at the outlet of the exhaust gas neutralizer.
The replacement of the oxygen concentration control sensor in the exhaust gas must be carried out in the following order. Read and record faults, eliminate faults and erase information from the memory unit of the ECU KSUD. Prepare the device "11.7.020". Remove the lower part of the microfilter housing and the protective casing of the injectors. Mark the plug connectors (SC) and the position of the oxygen concentration sensors in the exhaust gas. Loosen the clamp (11 and 12) of the fastening and release the sensor wires. Disconnect the SC from the oxygen concentration sensors.
Using the tool "11.7.020", unscrew the sensor from the manifold.
When installing the sensor, do not mix up its location. Apply a thin and even layer of grease such as "Never Seez Compound" only on its threaded part, on the new sensor it is already applied. Prevent grease from getting on the sensor surface that is in contact with the exhaust gas. Using the "11.7.020" device, screw in the sensor (M18x1.5) and tighten it to a torque of 50 N·m (5.0 kgf·m). Pay attention to the correct placement of the sensor wires. Check the recorded fault messages and erase them from the fault memory. When applying anti-corrosion protection to the underbody, the sensors should be insulated (covered).
The replacement of the oxygen concentration monitoring sensors in the exhaust gas should be carried out using a similar technology. In this case, when replacing the monitoring sensors (9 and 13, see Fig. 3.29) the protective cover of the injectors should be removed. Release the cable from the holders, disconnect the SS and remove the cable from the cable box on the rear side of the engine. If there is an automatic transmission, disconnecting the sensors for monitoring the operation of the 4th-6th cylinder neutralizer is possible only after removing the exhaust system.
To remove and install the sensors for monitoring cylinders 1–3, use the tool "11.7.030" (fig. 3.175), and for cylinders 4–6, the "11.7.020" device should be used.
Pay special attention to the correct installation of the oxygen sensor cables.