Heated Oxygen Sensor (Ho2S)
WARNING: This page is about a different car, the 1995 Ford Pickup, 1995 Ford Econoline, 1995 Ford Club Wagon, and 1995 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Vehicle may be equipped with one or 2 HO2S sensors. They are located in exhaust pipe, upstream of catalytic converters. Faults in sensor or circuit should set a diagnostic trouble code. See QUICK TEST in TESTS W/CODES - EEC-IV (4.9L) article. If no diagnostic trouble code has been set, see CIRCUIT TEST H in the appropriate TESTS W/CODES - EEC-IV (4.9L) article for additional sensor specifications and circuit testing procedures. Ensure that none of following conditions exist:
- Moisture inside sensor/harness connector.
- HO2S sensor coated with contaminants.
- Sensor circuit open or shorted to ground.