A failing Honda oxygen sensor will make the check engine light appear on your dash. When this occurs the driver of the Honda may not know what the problem is; just that the codes stored in the onboard computer need to be retrieved. The reason the oxygen sensor is needed when operating your Honda is the valuable information it is providing the computer. This sensor does not read exactly what the ambient level of oxygen is in the surrounding atmosphere. What the oxygen sensor actually does for your car is to compare the oxygen levels in the atmosphere as compared to what your engine in producing in its exhaust gases. This comparison is one of the necessary data points the computer uses to determine the correct air to fuel ratio so the engine can be operating at its maximum level of performance with relatively clean emissions. The location of the Honda oxygen sensor is on the exhaust pipe just aft of the exhaust manifold on your engine. It is the only object on this part of your car and can be easily recognized with the wire that is protruding from it. When it does fail and the check engine light appears on the dash, the code in the computer will indicate this is the faulty part. Replacing the oxygen sensor is an emission component the Honda owner can do themselves. The first step once it is known that the oxygen sensor is in need of replacing is that the battery will be disconnected. This will make it safe to remove this electrical component and also clear the stored codes in the onboard computer. Once the old sensor is removed and the new one is installed, the engine should operate as expected.