NTK 25616 Oxygen Sensor

Direct Fit Oxygen Sensor for Mercedes-Benz Applications

NTK 25616 is a direct fit heated oxygen sensor built for specific Mercedes-Benz applications from 2001-2011. It is designed to match OE fit, form, and function for upstream and downstream positions, including Mercedes-Benz C-Class, E-Class, G-Class, and SLK55 AMG fitments.

As part of NTK’s Direct Fit Oxygen Sensor line, this sensor reflects the brand’s focus on OE-style replacement coverage for import and domestic vehicles. NTK uses ceramic manufacturing expertise and extensive production testing to deliver a sensor that aligns with original equipment specifications.

Key Features

• Part number 25616 direct fit oxygen sensor
• Heated sensor design for faster operating temperature
• Specific fit for confirmed Mercedes-Benz applications
• 4-wire configuration with 35.5-inch wiring harness length
• 18 mm threaded mounting type
• OE-style replacement for upstream and downstream positions

Fitment and Application Details

Fits 2005-2011 Mercedes-Benz G55 AMG, downstream right and downstream left. Fits 2005-2011 Mercedes-Benz SLK55 AMG, upstream right and upstream left. Fits 2005-2008 Mercedes-Benz G500, downstream right and downstream left. Fits 2006-2007 Mercedes-Benz C280, downstream left. Fits 2006-2007 Mercedes-Benz C350, downstream left. Fits 2007 Mercedes-Benz ML500, upstream right and upstream left. Fits 2006-2007 Mercedes-Benz R500, upstream right and upstream left. Fits 2005-2006 Mercedes-Benz C55 AMG, upstream left. Fits 2006 Mercedes-Benz CLK500, upstream left. Fits 2001-2006 Mercedes-Benz CLK55 AMG, upstream left. Fits 2006 Mercedes-Benz E500, upstream right and upstream left. Fits 2002-2005 Mercedes-Benz C230, downstream. Fits 2003-2005 Mercedes-Benz C240, upstream left and upstream right. Fits 2003-2005 Mercedes-Benz C320, upstream left and upstream right. Fits 2004-2005 Mercedes-Benz CLK320, upstream left. Fits 2001-2002 Mercedes-Benz CLK320, upstream left. Fits 2003-2005 Mercedes-Benz CLK500, upstream left. Fits 2004-2005 Mercedes-Benz E320, upstream right and upstream left. Fits 2004-2005 Mercedes-Benz E500, upstream right and upstream left. Fits 2002-2004 Mercedes-Benz C32 AMG, upstream left. Fits 2004 Mercedes-Benz G500, upstream right, upstream left, downstream right, and downstream left by chassis break. Fits 2004 Mercedes-Benz G55 AMG, upstream right, upstream left, downstream right, and downstream left by chassis break. Fits 2003 Mercedes-Benz CLK320, upstream left. Fits 2001-2003 Mercedes-Benz CLK430, upstream left. Fits 2002-2003 Mercedes-Benz G500, upstream right and upstream left. Fits 2003 Mercedes-Benz G55 AMG, upstream right and upstream left. Fits 2001-2002 Mercedes-Benz C240, upstream left. Fits 2001-2002 Mercedes-Benz C320, upstream left. Fits 2001-2002 Mercedes-Benz E320, upstream right. Fits 2001-2002 Mercedes-Benz E430, upstream right. Fits 2002 Mercedes-Benz E55 AMG, upstream right. Fits 2001 Mercedes-Benz E55 AMG, upstream right.

What This Oxygen Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn sensor
• Slow sensor response during closed-loop operation
• Rough idle or drivability issues tied to exhaust feedback
• Failed emissions inspection caused by sensor degradation

Installation Notes and Tips

Confirm the sensor position before installation, since this application covers both upstream and downstream locations across multiple Mercedes-Benz models. Match the connector, wire length, and threaded mounting style to the original sensor, and verify chassis-specific notes where listed for 2004 G500 and G55 AMG applications. This part cross-references Bosch 16318 and DENSO Auto Parts 234-4893 for the same application.

Quality Assurance

NTK is the Sensor Specialist and a major original equipment oxygen sensor manufacturer. The brand states that these sensors are extensively tested during production to help ensure quality and reliability that meet or exceed OE specifications.