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. Top-rated performance: Oxygen Sensor (MPN ES21142-12B1) has a 12-month warranty!

About Delphi

Delphi is a trusted name in automotive technology, offering advanced solutions in fuel systems, electronics, and thermal management.

Why Choose Delphi?

• Delphi parts are known for their reliability – they’re built to last and keep your vehicle running smoothly. • They offer a wide range of parts for many different makes and models, so you're likely to find what you need. • Delphi invests in research and technology to make sure their parts meet or exceed original equipment standards. • You get a good balance of quality and price, meaning you don't have to compromise to get a dependable part. FixParts Online – Your Trusted Source for Quality Delphi Auto Parts.