When removing and installing oxygen sensors, save yourself the headache of removing other parts just to reach the dang thing with the ABN 02 Sensor Wrench 22mm Oxygen Sensor Wrench. It has a hex socket end to remove 22mm oxygen sensors (recommended for downstream) and includes a flex head and curved handle to offer clearance around exhaust pipes or access to sensors positioned upward and inward from the floorboard. This oxygen sensor socket wrench is made of cold-forged steel, and no additional tools are needed to remove most oxygen sensors (depending on sensor location). This O2 sensor socket wrench will save you the headache of removing other parts such as a catalytic converter to remove lower O2 sensors. Penetrating oil and anti-seize optional, not included. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.