The 95 V6 Duratec has two O2 sensors. They are in the manifolds, before the cat converters. Bank one is on the firewall side, and is more difficult to reach. Most people get to it from the underside.
Bank two is up front, and it's in the manifold near the oil filter.
Use an O2 socket to unscrew, it has a slot for the wires. If you replace, you can get OEM style (with connector attached), or replacement style, where you can cut off the connector half and splice it to the new wires. They are color coded. Replacement style has same sensor, but costs less. NAPA has them, also other auto stores. Bosch seems to be the preferred brand. Good Luck.
