Denso 234-4066 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor 234-4066

Denso 234-4066 is a specific-fit heated oxygen sensor built for downstream applications on select Chevrolet, Pontiac, and Saturn vehicles. It is engineered to match OE-style dimensions and connector layout for direct replacement service on the listed applications.

Key Features

• Heated oxygen sensor for downstream exhaust monitoring
• Specific fit design for direct replacement on listed vehicles
• 4-wire configuration with female connector
• Threaded mounting type with 0.708 in. thread diameter
• 27.95 in. wiring harness length
• OE Style construction for factory-like fit and function
• Built with Denso’s aluminum oxide trap layer to help protect the sensing element from silicone and lead contamination

OE Style Design and Application

The Denso OE Style line is built and tested to OE standards, with attention to exact replacement fit and consistent sensor performance. Part number 234-4066 is designed for downstream use on vehicles such as the 2006-2011 Chevrolet HHR, 2005-2010 Chevrolet Cobalt, and 2007-2010 Pontiac G5. It also fits multiple Saturn applications, including the Ion, Vue, L300, L200, LW200, L100, SC1, SC2, SL, SL1, SL2, and SW2. This part cross-references Bosch 13361 and NTK 21043 for the same application.

What This Oxygen Sensor Helps Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect exhaust oxygen readings affecting fuel control
• Reduced fuel economy caused by a worn sensor
• Slow sensor response after contamination or age
• Emissions test failures tied to sensor performance

Installation Notes and Tips

Fits 2006-2011 Chevrolet HHR, downstream; Fits 2005-2010 Chevrolet Cobalt, downstream; Fits 2007-2010 Pontiac G5, downstream; Fits 2005-2007 Saturn Ion, downstream; Fits 2006-2007 Saturn Vue, downstream; Fits 2002-2003 Saturn Vue, downstream; Fits 2005-2006 Pontiac Pursuit, downstream; Fits 2004 Saturn L300, downstream; Fits 2002-2003 Saturn L200, downstream; Fits 2002-2003 Saturn LW200, downstream; Fits 2002 Saturn L100, downstream; Fits 2000-2002 Saturn SC1, downstream; Fits 2000-2002 Saturn SC2, downstream; Fits 2000-2002 Saturn SL, downstream; Fits 2000-2002 Saturn SL1, downstream; Fits 2000-2002 Saturn SL2, downstream; Fits 2000-2001 Saturn SW2, downstream. Verify connector style, thread size, and harness routing before installation. Use the vehicle’s exact year, make, model, and downstream position to confirm application match. Denso 234-4066 is a direct replacement part for the listed OE-style applications.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for fit, function, and durability. The sensor’s protective trap layer is designed to help reduce contamination-related wear and support long service life in the listed applications.