2015 Lariat F-150 ecoboost 3.6 turbo. 105k miles.
Checked with my scanner and double checked at Autozone. MIL/Check engine code: P0131 = Bank 1 (Passenger/right side) Sensor 1 (Upstream/before cat. converter). Engine not running roughly but didn't want to wait for it to.
Motorcraft DY - 1185 ~$100 from Autozone and a direct fit. (However, quoted ~$185 from Ford).

- No ramps or jack. There was just enough room to get underneath the truck on my back.
- Disconnected negative cable from battery.
- Disconnected the undercarriage cover on the passenger side, enough to pull down and expose the exhaust pipe. Identify the sensor as the one just before the cat. converter and screwed into the pipe.
- Sprayed sensor to help free it with Krylon Tri-flow, assuming that it would be seized with corrosion. Left it for about an hour to soak.
- Followed the wire to the connector. It was pushed right back and out of the way so had to pull it down in order to unclip it. Used a long flat head screwdriver to push a retaining clip in and lever the connection apart.
- My 3/8" 22mm o2 socket from Amazon was out of shape and wouldn't fit so had to resort to a tightened adjustable wrench and leveraged against it with a breaker bar, being careful what used to anchor against. It shifted fairly easily.
- Removed the old sensor and replaced with the new as a direct fit. Used a bit of anti-seize on the thread although I think there was a little already on it. Connected up and pushed the connector back out of the way.
- Reconnected the undercarriage cover.
- Reconnected the negative.
- Drove it and checked that the codes had cleared.

Hope this helps a bit!