Originally intended to be an optional engine for the Ford Taurus in 1986, the 3.0-liter OHV V-6 engine came standard in the 1996 Taurus G and GL trim levels. Probably giving a nod to the mythical god of fire and ironworking, Ford named this fully cast-iron engine "Vulcan." The vehicle speed sensor -- part of the speed control system on your Taurus -- is mounted on the transaxle.
Park the Taurus on stable ground. Open the hood and allow the engine to cool. Locate the O2 sensor connector near the transmission dipstick tube and disconnect it.
Chock the rear wheels. Position a floor jack beneath the front jacking points located on the rails slightly inboard and to the rear of the front wheels. Lift the front of the car and support it on jack stands at the jacking points.
Working beneath the car, locate the remaining three O2 sensor connectors around the catalytic converter and disconnect them. Remove the four Y-pipe-to-exhaust manifold nuts from each exhaust manifold, using a ratchet, extension and socket. You may have to soak them with penetrating lubricant to get them loose.
Remove the retaining hardware from the catalytic converter-to-resonator flange, using a ratchet, extension and socket. Using tape and a marker, label each O2 connector to ensure that each is reinstalled in its original position.
Locate the exhaust hanger bracket at the front of the transaxle assembly. Loosen the nut at the slotted hole in the bracket, using a ratchet and socket, then remove the exhaust bracket mounting bolt while supporting the catalytic converter. Lower the catalytic converter and Y-pipe out of the vehicle.
Locate the vehicle-speed sensor and speedometer drive on the transaxle, in the area formerly covered by the Y-pipe and converter. Disengage the VSS shield. Using a ratchet and socket, remove the VSS mounting clip retainer bolt. Pull the VSS and gear assembly out of the speedometer housing.
Disconnect the speedometer cable and electrical cable from the VSS assembly. Remove the gear retainer from the VSS shaft, then slide the gear off the shaft. Retain the gear for reassembly. Remove the old VSS O-ring from the speedometer housing.
Lightly coat the new O-ring with transmission fluid, and wipe off the excess. Install the new O-ring in the speedometer housing bore, and ensure that it is fully and properly seated.
Install the gear and gear retainer onto the new VSS. Install the speedometer cable and the electrical connector. Insert the VSS into the speedometer housing bore. Install the retainer clip and bolt, then torque the bolt to 44 to 71 inch-pounds, using an inch-pound torque wrench and socket. Snap the sensor shield into place.
Hold the converter and Y-pipe assembly in position and install a bracket bolt loosely to support the weight. Install and torque the manifold-to-Y-pipe nuts to 25 to 33 foot-pounds, using a foot-pound torque wrench and socket.
Install a new gasket at the converter assembly outlet, then install and torque the hardware to 25 to 33 foot-pounds. Tighten the nut at the slot in the exhaust bracket securely. Plug in the three lower O2 sensor connectors. Lower the car to the ground. Plug in the upper O2 sensor connector near the transmission dipstick.
Start the engine and check for exhaust leaks. Test the car for proper operation.
