How replace toyota oxygen sensor | ehow, Slide under the vehicle with the socket set and locate the o2 sensor you will be replacing. sensor 1 is located on the exhaust pipe, on the left hand side of the. How clean o2 sensor | ehow, You may also like. how to clean oxygen sensors. your car's oxygen sensor is a vital component of the exhaust system. over time, oil, fuel and coolant can cause soot.