Oxygen Sensor: Service and Repair

REMOVAL
1. Disconnect negative battery cable.

NOTE: When battery voltage is removed from the Powertrain Control Module (PCM), all learned values will be cleared and reset to predetermined values. When battery voltage is restored to the PCM, the vehicle may exhibit certain driveability concerns. It will be necessary to drive the vehicle to allow the PCM to relearn values for optimum driveability and performance.

2. Disconnect Heated Oxygen Sensor (HO2S) from engine control sensor extension wiring.
3. Raise and support vehicle.
4. Remove HO2S from exhaust manifold outlet pipe, or dual converter "Y" pipe, using Oxygen Sensor Wrench T94P-9472-A.

NOTE: If excessive force is needed to remove HO2S, lubricate with penetrating lubricant E8AZ-19A501-B or equivalent prior to removal.

Heated Oxygen Sensor Location - 3.0L/4.0L Aerostar:

INSTALLATION
1. To install, reverse removal procedures If required, apply a light coat of anti-seize compound specification ESE-M12A4-A or equivalent to thread.
2. Tighten heated HO2Ss to 34-46 Nm (26-34 ft lb).