Guide And Manual

Bad oxygen sensor diagnosis

Some cars have two, three, or four oxygen sensors. The ON BOARD DIAGNOSTICS program should indicate a fault code when an oxygen sensor is malfunctioning. It should also tell you which O2 sensor is sending bad information. If you have more than 50,000 miles on your car, you should change all your O2 sensors. Expensive. Be careful, the O2 sensors are not identical and must be placed in the correct position.

 A defective O2 sensor would likely be sending a constant 1.0 Volt air/fuel signal to the computer brain to cause such high fuel consumption.