Must Know Before Buying:

The following information is for instructional and guidance reference only. We try and make them as accurate as we can.
If Check Engine Light is on or an OBDII Trouble/Fault code occurs after installation, check the sensor with a voltmeter as below. If the sensor is good, further diagnosis is required. There're many different codes for specific functional failures, which are NOT necessarily relevant to the sensor. Find out what the Code means before leaving any feedbacks.
Items that have been installed, altered or contaminated are non-returnable. ONLY a defective sensor after tested by a voltmeter is applied to manufacturer warranty.
 
What is a California emissions sensor? How do I know if I need one?
 
A California emissions O2 sensor is meant for vehicles that are designed to meet California emission regulations. Such vehicles should have a sticker under the hood or on the driver’s door jamb that identify them.