NTK 25627 Oxygen Sensor - Downstream Left or Downstream Right

Direct-Fit Oxygen Sensor

NTK 25627 is a specific-fit heated oxygen sensor built for downstream applications with OE-style form and function. It uses a threaded mounting design and a 4-wire configuration for direct replacement service on select BMW and Rolls-Royce models.

Key Features

• Specific-fit oxygen sensor for direct replacement service
• Heated sensor design for faster operating response
• 4-wire construction with a 17.75-inch harness length
• Threaded mounting with an 18 mm thread diameter
• OE-equivalent design for downstream sensor applications

Detailed Description

NTK 25627 is part of the Direct Fit Oxygen Sensor line, a product line focused on application-specific replacement sensors with OE-style fit, form, and function. NTK is known for oxygen sensor manufacturing and uses ceramic technology and manufacturing controls from raw material through finished sensor production. This part number is engineered for downstream use on BMW M5, BMW M6, BMW 760i, BMW 760Li, BMW X5, BMW 545i, BMW 645Ci, BMW 745i, BMW 745Li, BMW Alpina B7, and Rolls-Royce Phantom applications listed in the fitment data.

Fits 2006-2010 BMW M5, downstream right and downstream left. Fits 2006-2010 BMW M6, downstream right and downstream left. Fits 2007-2008 BMW Alpina B7, downstream right and downstream left. Fits 2007 Rolls-Royce Phantom, downstream right and downstream left. Fits 2004-2006 BMW 760i, downstream right and downstream left. Fits 2003-2006 BMW 760Li, downstream right and downstream left. Fits 2004-2006 BMW X5, downstream right. Fits 2004-2006 Rolls-Royce Phantom, downstream right and downstream left. Fits 2004-2005 BMW 545i, downstream right and downstream left. Fits 2004-2005 BMW 645Ci, downstream right and downstream left. Fits 2002-2005 BMW 745i, downstream right and downstream left. Fits 2002-2005 BMW 745Li, downstream right and downstream left.

What It Helps Address

• Faulty downstream oxygen sensor readings
• Check engine light concerns related to sensor performance
• Incorrect air-fuel feedback from a worn sensor
• Slow sensor response from aging heated elements
• Replacement needs after sensor contamination or electrical failure

Installation Notes and Tips

Confirm the downstream left or downstream right position before ordering, since the fitment varies by application. Match the threaded mounting style, wire count, and harness length to the original sensor. This part cross-references Bosch (e.g., 15321, 15339) for the same application.

Quality Assurance

NTK states that its oxygen sensors are extensively tested during manufacturing to meet or exceed OE specifications. The brand is part of the NGK family and is recognized as a major original equipment oxygen sensor supplier.