Front Oxygen (A/F) Sensor: Inspection

1. Check that the front oxygen (A/F) sensor has no deformation, cracks or other damages.
2. Measure the resistance between front oxygen (A/F) sensor terminals.

Fig 1: Measuring Resistance Between Front Oxygen (A/F) Sensor Terminals

Courtesy of SUBARU OF AMERICA, INC.

Terminal No.	Standard
3 and 4	2.4±0.24 Ω (when 20°C (68°F))