Heated Oxygen Sensor (Ho2S): Removal
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1998 Mazda Protege, 1998 Mazda Millenia, 1998 Mazda MPV, 1998 Mazda B4000, and 1998 Mazda B3000. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect oxygen sensor electrical connector. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). If sensor is difficult to remove, use rust penetrant to avoid damaging threads. Using appropriate oxygen sensor socket, carefully remove sensor.