Attention! Since 1996, the vehicles in question have been equipped with an electronically controlled recirculation system valve. The electronic recirculation system is checked at the dealer's service center.
1. The EGR valve is mounted on the intake manifold, next to the throttle body. As a rule, the reason for the unsatisfactory operation of the EGR system is the sticking or corrosion of the valve.
2. On a cold engine, check the diaphragm movement by pressing on it with your finger (see photo). The diaphragm should be fully inserted into the valve body with a slight force.
3. If the diaphragm moves a small distance, compare the diaphragm stroke of the old and new valves. If resistance to the diaphragm movement is felt, replace the recirculation valve.
4. Some vehicles are equipped with an electronic pneumatic distributor ("VRV valve"), which is mounted on a bracket near the recirculation valve. The pneumatic distributor filter should be periodically removed and washed with a soap solution.