NTK 21053 Oxygen Sensor - Downstream, Downstream Left or Downstream Right

Direct Fit Oxygen Sensor for OE Applications

NTK Direct Fit Oxygen Sensor 21053 is a heated, specific-fit replacement built for emission control service where accurate exhaust feedback matters. It is engineered with a threaded mounting design, 18 mm thread diameter, 4-wire construction, and a 42.25 in. wiring harness length for direct replacement on confirmed applications.

Compatible With Chevrolet Classic, Pontiac Grand Am, Chevrolet Corvette, and Oldsmobile Alero applications listed below, this NTK oxygen sensor supports downstream monitoring with OE-style fit, form, and function. Part number 21053 is also cross-referenced to Bosch 15900 for the same application.

Key Features

• NTK Direct Fit Oxygen Sensor, part number 21053
• Heated sensor design for downstream exhaust monitoring
• Specific-fit replacement for confirmed vehicle applications
• 4-wire configuration with threaded mounting
• 18 mm thread diameter and 42.25 in. harness length
• Built by NTK, a major OE oxygen sensor manufacturer

Product Details

NTK’s Direct Fit Oxygen Sensor line is designed for import and domestic coverage with OE application support. NTK uses ceramic manufacturing expertise and controlled production processes to maintain consistency from raw material through finished sensor. For this part, the focus is on direct replacement performance, correct connector-style fitment, and reliable downstream exhaust signal delivery on the listed Chevrolet, Pontiac, and Oldsmobile applications. If you are replacing a worn downstream sensor on a 2004-2005 Chevrolet Classic, 2002-2005 Pontiac Grand Am, 2004 Chevrolet Corvette, or 2002-2004 Oldsmobile Alero, part number 21053 matches the specified application data.

What This Sensor Helps Address

• Check engine light related to oxygen sensor circuit faults
• Slow or inaccurate downstream oxygen sensor readings
• Emission control issues tied to aged sensor response
• Incorrect fitment from universal-style replacement sensors
• Exhaust monitoring problems on OE-equivalent replacement jobs

Installation Notes and Tips

• Verify the vehicle position before ordering: downstream, downstream right, or downstream left as listed.
• Confirm the 18 mm threaded mounting style matches the original sensor location.
• Check harness routing and connector reach against the 42.25 in. lead length.
• Use the vehicle’s service information for torque and connector handling procedures.
• Inspect the exhaust bung and wiring path before installation to avoid thread or harness damage.

Quality Assurance

NTK is the sensor specialist within the NGK family of products and is a large OE oxygen sensor supplier. This part is manufactured and tested to meet or exceed OE specifications for fit and reliability on the listed applications.