OEM replacement Oxygen Sensors!
Oxygen sensors (also known as O2 sensors, Air-Fuel Ratio Sensors, Air/Fuel Sensors, or lambda sensors) are an essential part of modern fuel and emissions systems. They provide the vehicle's electronic control units with the information necessary to maintain the proper air-fuel ratio as well as emissions which fall within government requirements.
Oxygen sensors can fail over time, requiring them to be replaced or the car's ECU winds up defaulting to what it believes is the best air-fuel mix, which results in poor performance and fuel economy. In most cases, a trouble code will be registered and can be identified by using an on-board diagnostics tool to retrieve the code.
Modern vehicles are equipped with multiple sensors, often times four can be used for one vehicle! Upstream and downstream are the most common identifiers for location, although sometimes a "bank" system will be used to identify which pipe they bolt into. Upstream refers to positions before the catalytic converter, and downstream refers to the positions after the converter.
We have a great deal of direct fit and universal Oxygen Sensors from these vendors: