NTK 23551 Oxygen Sensor - Upstream, Upstream Left, Upstream Rear or Upstream Right

Direct Fit Oxygen Sensor for OE-Style Replacement

The NTK Direct Fit Oxygen Sensor 23551 is a heated, specific-fit replacement built for precise air-fuel monitoring in select Mitsubishi, Chrysler, and Dodge applications. It is engineered with a threaded mounting design and a 4-wire harness to match the original sensor layout for direct replacement service.

NTK is known for oxygen sensor coverage across import and domestic vehicles, and this part reflects that focus with OE-style fit, form, and function. It is a strong match for drivers searching for a 2001-2005 Mitsubishi Eclipse upstream oxygen sensor, a 2001-2005 Chrysler Sebring Bank 1 Sensor 1 replacement, or a 2008-2010 Mitsubishi Lancer upstream sensor for California emissions applications.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for direct replacement service
• 4-wire configuration with 27.5 in. wiring harness length
• Threaded mounting type with 18 mm thread diameter
• OE-style design for select upstream and upstream rear applications
• Part number 23551 for catalog and cross-reference lookup

Application Details

Compatible With select Mitsubishi Endeavor, Lancer, Eclipse, Diamante, Galant, and Montero applications, plus Chrysler Sebring and Dodge Stratus models listed in the fitment data. This NTK oxygen sensor 23551 is used in upstream and upstream rear positions, including Bank 1 Sensor 1 applications and California emissions configurations where specified.

This part cross-references Bosch 13529 and DENSO Auto Parts 234-4135 for the same application.

What This Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn upstream sensor
• Slow sensor response affecting fuel control feedback
• Emissions test failures tied to sensor degradation
• Fault codes associated with heated oxygen sensor circuits

Installation Notes and Tips

• Verify the vehicle’s year, make, model, and sensor position before ordering.
• Match the original connector, wire count, and threaded mounting style to the removed sensor.
• Confirm upstream, upstream rear, or Bank 1 Sensor 1 placement using the vehicle service information.
• Inspect the exhaust bung threads before installation to ensure proper seating.
• Clear diagnostic trouble codes after installation and confirm closed-loop operation.

Quality Assurance

NTK manufactures oxygen sensors with controlled ceramic technology and extensive production testing to meet or exceed OE specifications. The brand’s OE-focused engineering and application coverage support dependable replacement performance for Mitsubishi Eclipse, Mitsubishi Galant, Mitsubishi Lancer, and related listed vehicles.