About SANGYUE We have been producing O2 sensors for over 15 years. We provide professional solutions for the automotive aftermaket. Stable quality earned us lots of customers. We are not an OE supplier, but we reverse-engineered the product and create the same production line as the OE sensors to produce the oxygen sensor. Oxygen Sensor Position Confirmation! Identification of bank 1/bank 2/upstream/downstream according to your vehicle's engine type 1-10 Steps To Replace The Defetcive Sensor And Tackle The Faulty Codes！ Be sure to follow proper diagnostic procedures to determine whether a part has failed.