You will find your GMC Sierra oxygen sensor located near your exhaust manifold, where it performs a very important job. The Sierra oxygen sensor is responsible for monitoring the oxygen content of the exhaust leaving your cylinders. Why is this important? Your engine strives for a precise oxygen to fuel ratio of 14.7 to 1, which creates optimal fuel efficiency.

When your GMC Sierra oxygen sensor is not working right, your vehicle’s onboard computer has to rely on other sensors in the network to obtain this information, and since these sensors are not located near the exhaust path, the data from them is only an estimate. This means your engine will waste gas, because too much fuel will be injected rather than too little.

If your engine does not receive enough fuel, it can be damaged. There are a number of reasons your Sierra oxygen sensor may fail. It might simply wear out over time due to normal use. Also, if your GMC Sierra oxygen sensor is contaminated by engine oil, antifreeze, gasket sealant, or certain fuel additives, it will no longer work. Unfortunately, it can be hard to tell when your Sierra oxygen sensor is having problems. Some of the symptoms of a faulty oxygen sensor include poor engine running, lowered fuel economy, and black, foul-smelling exhaust smoke, but these symptoms can also be caused by other engine problems. A bad oxygen sensor is most often detected during an emissions test, or while you are having other exhaust work done. You should replace your oxygen sensor at least every 100,000 miles.Find the oxygen sensor you need here in our extensive online catalogue for less.