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. Reliable performance guaranteed: Oxygen Sensor (MPN ES20638-12B1) has a 12-month warranty!

About Delphi

Delphi is a trusted American brand in automotive technology, offering advanced fuel and electronic systems. Based in the USA, Delphi remains at the forefront of innovation and performance.

Why Choose Delphi?

• Delphi parts are built to last, using quality materials so you can drive with confidence. • We offer a wide range of parts for many different vehicles – from everyday cars to trucks. • Delphi parts are tested rigorously to meet or exceed industry standards, giving you reliable performance. • You’ll get a great value with Delphi – quality parts don’t have to break the bank. Delphi delivers excellence, FixParts Online delivers to your door.