To check if the lambda sensor is operable, you will need a multimeter. This procedure involves several stages. First, make sure that a sensor heater receives the voltage.

To do this, switch on the ignition and attach multimeter probes to the connectors of the wires going to the heater. Then carefully start the engine. Indicated voltage is supposed to be 12 V. Having unplugged the connector, attach probes to heater wires to test it. If there is no resistance, then the lambda sensor should be replaced.

Once the ignition is switched on, it is recommended to check whether there is reference voltage between the signal wire and chassis. The voltage should be 0,45 V. The lambda sensor signal is checked after the engine is heated up to the operating temperature. Voltage between the signal wire and chassis at 3 000 rev per minute is supposed to be between 0,1 - 0,9 V. Detailed instructions can be found in video tutorials.

The lambda sensor can be installed in different parts of the exhaust system. Two lambda sensors are usually used in modern vehicles: an upper sensor, installed in an exhaust manifold before a catalyst, and a lower one - placed after a catalyst.

The lambda sensor is sometimes installed in a headpipe before a catalyst. To detect this spare part exact location that depends on a vehicle design features, namely on an engine type, read the vehicle's technical documentation.

Once the lambda sensor is faulty, it often causes other car systems to malfunction. Most common lambda sensor failure symptoms are:

• increase of fuel consumption;
• unstable motor operation;
• vehicle jerking movements at driving;
• increased toxicity level of exhaust gases;
• unusual (popping) sounds produced by the power unit;
• engine power reduction;
• slow response when pressing the accelerator pedal;
• black smoke coming out of the exhaust pipe;