How do you replace an O2 sensor in a 1995 Subaru Legacy?

Answer 1

Presume you are talking about the main Oxy sensor mounted on the front of the front catalytic converter, between where the 2 pipes come together. Best to work on a cold/or cool engine. Raise car onto jackstands (or use car ramps), and work from underneath. Use one of the oxygen sensor removal tools, unscrew old sensor, unthread wires, unplug, then reverse to replace. Tighten until the gasket crushes a bit, keep tightening until effort suddenly increases--stop right there. Plug the sensor wires back into the car socket, and make certain that none of the wires will touch the hot exhaust parts. Note-- your old sensor may be stuck, and the best tool for removal is one looking like a fat crow's foot wrench, with a 3/8 inch socket hole on one side. The sockets which are just deep sockets with a side machined out of them are not strong enough, and likely will not fit into the tight area where Subaru puts the sensor. Try to buy a sensor with the correct Subaru plug already installed, it is far easier to hook up.