Each of the 2002 Honda Civic models have two oxygen sensors around the engine. The sensors are found in two different locations depending on the model owned.
Parts salesman Robert Canedo of Dobbs Honda in Tucson, Arizona, explained that the oxygen sensors are off the manifold on the DX and LX models. One sensor is upstream or before the catalytic converter, and the other is downstream or after it. On the EX model the oxygen sensors are under the vehicle, below the engine. One is inside the catalytic converter, and the other is upstream.
Oxygen sensors connect via two or four wires to the engine and computer and monitor the amount of oxygen in gas as it travels through the engine. Properly functioning oxygen sensors promote fuel efficiency.
Replacement oxygen sensors start at $20 and can cost as much as $300 each depending on the manufacturer of the part and the model of the Honda Civic.
