If your car is emitting black smoke or exhaust with a rotten egg odor, or you are experiencing poor engine performance or a drop in fuel economy, you may have a faulty BMW 528i oxygen sensor. Your 528i oxygen sensor, also called an O2 sensor, is the only sensor in the network that monitors your engine exhaust located near the exhaust manifold. The BMW 528i oxygen sensor measures the oxygen content of your exhaust as it leaves the cylinder.

The optimal oxygen-to-fuel ratio for your engine is 14.7 to 1, and that number is what your 528i oxygen sensor strives for. The BMW 528i oxygen sensor checks this super-hot exhaust hundreds of times per minute and transmits the information to your car's computer.

When your 528i oxygen sensor is not working properly, your car has to rely on the other sensors in the network to determine the amount of fuel it injects into the combustion chambers. Unfortunately, none of the other sensors are near the exhaust, and your car relies on estimated data. This means that a bad BMW 528i oxygen sensor will end up wasting gas, since your car will inject too much fuel rather than risk damaging other engine parts with too little fuel. Over time, excess fuel usage caused by a faulty 528i oxygen sensor will damage your catalytic converter as well. It can be difficult to diagnose a bad BMW 528i oxygen sensor. The problem can sometimes be spotted if your car fails an emissions test. A diagnostic check can also detect a faulty 528i oxygen sensor, but this test is not always accurate as your BMW 528i oxygen sensor may be working sporadically.If you suspect your 528i oxygen sensor is not working, order a replacement BMW 528i oxygen sensor from our extensive online catalogue.