These little guys measure the amount of unburned oxygen leaving your engine. Basically, they’re constantly checking what’s coming out of the exhaust. They send that information back to your car’s computer – the engine control unit, or ECU – as an electrical signal. Different sensors will read before or after the catalytic converter, and that changes what they’re checking for. Think of it like this: the ECU is trying to get the perfect fuel – air mixture for your engine to run efficiently. The oxygen sensor is its eyes and ears. It's telling the computer “Hey, there’s too much oxygen, lean it out a bit,” or “Not enough oxygen, add a little fuel.” It's a closed – loop system, so it's constantly adjusting to keep things running smoothly. There are usually multiple oxygen sensors in most modern vehicles – one before the catalytic converter and then at least one after. If an oxygen sensor goes bad, the ECU gets inaccurate information. This throws off the fuel mixture, and you’ll notice if that happens. Typically, you'll see a drop in gas mileage, rough idling, or even a failing emissions test. Sometimes it might even trigger your check engine light. A bad sensor can also potentially damage your catalytic converter over time, which is a much more expensive repair. We carry a good selection of these at Fixparts Online, and it's often something a good DIY mechanic can handle, but if you're not comfortable, definitely have a professional take a look. They really are key to keeping everything balanced and running right. Premium parts, premium warranty: Oxygen Sensor (MPN 40917536) has a 12-month guarantee!

About SWAG

SWAG, part of the Ferdinand Bilstein Group, produces precision-engineered spare parts for suspension, steering, and engine systems.

Why Choose SWAG?

• SWAG parts are made to the same high standards as the original parts your car came with, so you get reliable performance. • We offer a wide range of parts, covering many different car makes and models – chances are we have what you need. • SWAG parts are a smart choice for your wallet. You get quality without paying extra for a fancy name. • Professional mechanics trust SWAG. We’re a brand known for consistently delivering dependable parts. Drive with confidence – choose SWAG parts at FixParts Online.