NECATUO O2 Oxygen Sensor 4016021 Direct-Fit Replacement for Polaris RZR & ATV — OEM-Quality

NECATUO 4016021 is a direct-fit OEM-quality oxygen (O2) sensor designed to replace Polaris part numbers 4013979 and 4016021, restoring accurate air-fuel monitoring for compatible Polaris ATVs, UTVs and motorcycles.

This replacement O2 sensor is built to the original equipment fit and electrical specifications so it installs with minimal fuss and returns the engine control unit precise exhaust oxygen data. Constructed from durable materials, the NECATUO sensor aims to provide reliable operation across varied riding conditions while helping the vehicle manage fuel trimming and catalytic converter life.

Which Polaris models does this NECATUO oxygen sensor fit?

This sensor is compatible with a wide range of Polaris model years and configurations. Always verify fitment against your vehicle's year and part numbers before ordering.

• RZR XP 1000 and RZR XP 4 1000 (2015–2019), including Turbo variants (2016–2019)
• General 1000 models (2016–2019) and several Ranger/Scout/Chief/Chieftain Roadmaster models listed for 2014–2016
• Sportsman series quads (various 2015–2016 models) plus smaller Off-road models noted in the full fitment list
• Replaces OE references 4013979 and 4016021 — confirm these numbers match your vehicle

How does this replacement sensor affect engine performance?

The O2 sensor provides the engine control module with exhaust oxygen readings used to adjust the air-fuel mixture in real time. Installing a correctly functioning sensor helps the ECU optimize combustion, which can improve drivability and throttle response under many operating conditions.

• Restores accurate air–fuel feedback for smoother idle and acceleration
• Supports proper fuel trim adjustments to avoid overly rich or lean running
• Helps maintain catalytic converter efficiency by preventing extreme mixture errors

Is installation straightforward and what should I expect?

The NECATUO 4016021 sensor is manufactured to match the original equipment's form, fit, and electrical connector, so installation is typically direct without modification. Basic mechanical tools and standard sensor socket access are usually all that’s needed.

• OE-style connector and thread pitch for plug-and-play replacement
• Designed for long-term durability under heat and vibration
• Follow torque specs and connector seals to prevent exhaust leaks

Will this sensor trigger diagnostic codes or need programming?

When the replacement matches the original part number and wiring, it normally communicates with the vehicle ECU without additional programming. If a check-engine light remains after installation, verify connector seating, wiring continuity, and that the correct OE reference was used.

• Direct-fit replacement for OE 4013979 / 4016021 minimizes ECU compatibility issues
• Clear stored codes after installation using an OBD tool if necessary
• Inspect wiring and harness for damage before assuming sensor failure

Who is this for? Riders and technicians who need a reliable, OEM-spec oxygen sensor replacement for Polaris RZR, General, Ranger, Chieftain/Chief and Sportsman models listed in the fitment details. Choose the NECATUO 4016021 when you want a cost-effective, direct-fit sensor built to original specifications and backed by clear OE reference numbers; verify your vehicle’s year and part number compatibility before purchase.