NGK 21507 Direct Fit Oxygen Sensor, 4-Wire Heated O2 Sensor

The NGK 21507 oxygen sensor (also called an O2 sensor or NTK air-fuel ratio feedback sensor) is a direct-fit, OE-type replacement. It measures the oxygen content of the exhaust and reports it to the engine control unit (ECU). The ECU uses that signal to keep the air-fuel ratio in closed-loop control, which supports engine performance, fuel efficiency and low emissions.

Key Features:

• Direct-fit design: an OE-equivalent replacement that does not need splicing.
• Heated, 4-wire switching sensor: the heater brings the sensor to operating temperature quickly.
• 18mm thread diameter.
• Advanced ceramic sensor element: a 3-stage plasma jet and deposit trap overcoat resists contaminants and element poisoning.
• Dual-coated platinum interface and thinner ceramic element: designed for fast light-off and response times.
• OE-specified water-resistant connector and harness hardware: helps make installation easier.
• OE-style testing: development includes vibration and thermal shock testing.

Cross References: NTK 21507, Denso 234-4129, Denso 234-4731, Delphi ES20031, Spectra Premium OS5069, Carquest 75-1898, Carquest 75-3274, Carquest 75-3433, Suzuki 18213-65D10, Suzuki 18213-65D32.

NGK/NTK is a major OEM supplier of oxygen sensors. A worn or contaminated sensor can cause poor fuel economy, rough running and a check engine light, so replacing it restores accurate fuel-trim feedback to the ECU.