Glossary / Engine

O2 sensors

12 Episode Mentions

Too Afraid to Ask

O2 sensors are parts in a car that check how much oxygen is in the exhaust. They help the engine run better and cleaner by making sure the right amount of fuel is used.

Technical Definition

O2 sensors, or oxygen sensors, are critical components in a vehicle's exhaust system that measure the amount of oxygen in the exhaust gases. This information helps the engine control unit (ECU) optimize fuel efficiency and reduce emissions.

Hear It Discussed

"I really think it was 1980 was first year of O2 sensors, which is what forced a lot of cars to not be able to be available here anymore."
FIXED: The One-Year Garage: 1980 Bring a Trailer Podcast 26:13

"...monitor the O2 sensors for a change immediately after a refuel. Now if you don't drive it if you refill it and drive right around the corner of your house and turn it off..."
Automotive Questions Like How To Choose a Tow Vehicle and More LIVE Under The Hood show 10:25

"There aren't vehicles out there that have O two sensors preach cylinder every yeah, yeah, right, that's not that's not how it works."
Ron Ananian, The Car Doctor - May 16, 2026 - Hour 2 Ron Ananian The Car Doctor 29:08