2016-2019 BMW 7 Series 4.4 Oxygen Sensor 808974

Also known as

O2 Sensor

Lambda Sensor

Air Fuel Ratio Sensor

Oxygen Probe

Exhaust Gas Sensor

O2S

What this part does

The Oxygen Sensor measures the proportion of unburned oxygen present in the exhaust gases as they exit the engine manifolds. It relays this real-time voltage data to the engine control module, allowing the system to continuously adjust the air-fuel mixture for optimal combustion and emissions control. Depending on its specific position on the exhaust pipe, it either dictates fuel trim adjustments or monitors the efficiency of the catalytic converter. When this component fails or degrades, it typically triggers a check engine light, causes a noticeable drop in fuel economy, and can lead to a rich running condition, rough idling, or engine hesitation.

Fits these vehicles

OEM and interchange numbers

808974

Before you order

Modern vehicles use multiple oxygen sensors that are specific to their location on the exhaust system. You must verify whether you need an upstream (Sensor 1, before the catalytic converter) or downstream (Sensor 2, after the catalytic converter) unit, as well as the specific engine bank (Bank 1 or Bank 2). While the sensors themselves function similarly, the wire harness length and the physical connector plugs are unique to each position and will not interchange. Always compare the connector on your failed unit with the images provided to ensure a proper fit. It is highly recommended to inspect the wiring harness on the vehicle for melting or abrasion before installing the replacement.