These little guys actually measure the amount of oxygen left over after combustion in your engine. They send that information to the car’s computer – the engine control unit, or ECU – so it can figure out if the engine is running lean (too much air, not enough fuel) or rich (too much fuel, not enough air). It's a feedback system, constantly adjusting things to keep everything running smoothly. There are usually multiple sensors – one before the catalytic converter, and one after, to check the converter is doing its job too. Think of it like this: the ECU is the brain, and the oxygen sensor is giving it vital information about what's happening in the engine. The ECU uses that info to fine – tune the fuel mixture. It directly affects how efficiently your engine runs, and how clean the exhaust is. A healthy oxygen sensor is key to hitting those emissions standards. If an oxygen sensor fails, your car's fuel economy will likely drop. You might notice your car struggling to accelerate, or idling roughly. The check engine light will almost certainly come on – it's usually one of the first things that triggers it. A bad sensor can even damage your catalytic converter over time, which is a much more expensive repair. They don't last forever, and eventually they just get slow to respond or inaccurate. Fixparts Online has a pretty good selection of these, and replacing them is often a straightforward job, though sometimes they can be a little tricky to get to because of where they’re located in the exhaust system. You’ll notice if one goes bad, usually with a drop in gas mileage and that engine light. Shop with confidence: Oxygen Sensor (MPN 21437) comes with a 3 year manufacturer guarantee!

About Febi

Ferdinand Bilstein is well known for reliability and is trusted by repair professionals worldwide.

Why Choose Febi?

• Febi parts are made to the same standards as original equipment, so you get reliable quality. • We offer a really wide range of parts, covering most makes and models – meaning you can likely find everything you need in one place. • Febi has been around for over 75 years, so we know a thing or two about auto parts and what mechanics need. • Our parts are priced fairly, giving you a great balance between quality and cost. Febi delivers excellence, FixParts Online delivers to your door.