Downstream Oxygen Sensor - P5 XC90 S90 V90, to 2017

Oxygen sensors are able to determine how clean and complete an engine is burning its fuel by measuring the amount of oxygen in the exhaust: less oxygen means a complete fuel burn, as all available fuel is combining with all available oxygen. This ideal ratio of fuel to air is called the "stoichiometric" ratio, and modern engines with the help of O2 / Lambda sensors run pretty close to this ratio.

Modern cars have at least two oxygen sensors: an upstream sensor (right outside the cylinders) which measures how completely the engine is burning fuel, and a downstream sensor (after the catalytic converter) which measures catalyst efficiency.

If you've got catalytic converter error codes like "catalyst efficiency below threshold" or other rear O2 sensor error codes, this OES Denso oxygen sensor will get you back to emissions inspection readiness again.

Additional Keywords: O2 LAMBDA 02 REAR

Product Fitment Notes & Potential Issues

This fits cars with CC01 "first generation VEP4" engines, split is late in the 2017 model year. If you have a late 2017 or early 2018 car, we suggest checking your car's variant codes by plugging your VIN in to VIDA before ordering; if you do not have access to VIDA, call your dealer or IPD Customer Service with your VIN and we can look it up for you.