Denso 234-8012 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor 234-8012

Denso 234-8012 is an OE Style heated oxygen sensor built for direct replacement on select BMW applications. It is engineered for exact fitment and consistent signal performance, with a threaded mounting design and a 4-wire male connector for downstream locations.

Key Features

• Heated oxygen sensor for downstream exhaust monitoring
• Specific fit design for select BMW models
• 4-wire configuration with male connector
• Threaded mounting type with 0.705 thread diameter
• 20.71 in. wiring harness length
• OE Style construction for direct replacement use

OE Style Construction

Denso’s OE Style line is built to match original equipment fit and function for a first-time fit on the vehicle. The sensor uses an aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination, supporting stable operation and long service life. This makes Denso 234-8012 a practical replacement for BMW 440i, 540i, 740i, X3, and related applications where downstream oxygen sensor performance matters.

This part cross-references BMW 11788611294 and NTK 25768 for the same application.

Vehicle Fitment

• Fits 2021 BMW M240i, downstream
• Fits 2021 BMW M240i xDrive, downstream
• Fits 2017-2020 BMW 440i, downstream
• Fits 2019-2020 BMW 440i Gran Coupe, downstream
• Fits 2017 BMW 440i Gran Coupe, downstream
• Fits 2017-2020 BMW 440i xDrive, downstream
• Fits 2017-2020 BMW 440i xDrive Gran Coupe, downstream
• Fits 2017-2020 BMW 540i, downstream
• Fits 2017-2020 BMW 540i xDrive, downstream
• Fits 2016-2020 BMW 740i, downstream
• Fits 2017-2020 BMW 740i xDrive, downstream
• Fits 2017-2020 BMW M240i, downstream
• Fits 2017-2020 BMW M240i xDrive, downstream
• Fits 2018-2020 BMW X3, downstream
• Fits 2017-2019 BMW 340i GT xDrive, downstream
• Fits 2018-2019 BMW 640i xDrive Gran Turismo, downstream
• Fits 2016-2018 BMW 340i, downstream
• Fits 2016-2018 BMW 340i xDrive, downstream
• Fits 2018 BMW 440i Gran Coupe, downstream
• Fits 2018 BMW 750i, downstream

What It Helps Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect exhaust oxygen readings affecting fuel control
• Slow sensor response from a worn heated O2 sensor
• Emissions test failures tied to sensor performance
• Rough running or reduced fuel efficiency caused by inaccurate feedback

Installation Notes

Verify the connector style, thread diameter, and downstream location before installation. This is a specific-fit sensor, so matching the BMW application and position is important for proper operation. Inspect the harness routing and exhaust threads during replacement to ensure the sensor seats correctly and the wiring is kept clear of heat sources.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for direct replacement use. The OE Style design focuses on accurate fit, stable performance, and durability in demanding exhaust conditions.