Heated Oxygen Sensor.
Oxygen Sensor.

• Monitors the air-to-fuel ratio within your engine
• Can become worn over time or damaged by a fluid leak
• Replacement by an INFINITI professional is recommended

Your vehicle's combustion system depends on various sensors to maintain optimal conditions for performance. One of these mechanisms is the O2 or Oxygen Sensor (Rear). Originally, they were introduced to help control and curb emissions, and they can be found in the large majority of cars on the road today. Depending on the INFINITI model and year you own, your engine may have one or more sensors.

Your INFINITI's O2 sensors help gauge the air-to-fuel mixture, working with the internal computer to regulate said ratio depending on whether your engine is running on too little oxygen (burning rich) or burning lean (too much oxygen). An “off” air-to-fuel ratio can affect your engine combustion performance, leading to poorer fuel efficiency and more emissions. That's one reason why it's so important to get a genuine INFINITI Oxygen Sensor (Rear).

An Oxygen Sensor (Rear) makes electricity, and the amount of voltage it results in depends on what the exhaust system is producing. Simply put, the voltage generated by the Oxygen Sensor (Rear) will vary if the fuel-air mixture is off! When a variance in voltage is detected, your engine's internal computer adjusts the ratio to keep it running as designed.

Your vehicle's O2 sensor may need to be replaced due to regular wear and tear. In some cases, your car may need a premature O2 sensor replacement if your INFINITI sensor is damaged by coolant or oil leaks, or other forms of contamination. Some potential signs that it's time for a new INFINITI sensor include: engine misfiring, loud idling, decreased fuel efficiency, and an illuminated dashboard warning light.

Since the majority of modern cars rely on multiple O2 sensors to support proper combustion, it can be hard for an at-home mechanic to pinpoint which one requires replacement! Sometimes, the process involves a specialized code scanner and jacking the vehicle up to get to the undercarriage. Accordingly, many INFINITI drivers opt for getting Oxygen Sensor (Rear) repairs with their local INFINITI technicians.

Are you noticing common signs of Oxygen Sensor (Rear) failure? Get an OEM replacement sensor for your INFINITI M45 or INFINITI Q45 for precise fitment and performance. Click on the What This Fits tab for more information.

Fits M45, Q45