I want to replace both the Upstream and Downstream O2 Sensors (there are a total of 3 sensors on my Lancer, but the center sensor has been replaced already). I've seen a couple of YouTube videos that show the upstream sensor. You have to go under the carpet in the front passenger floor area to access the wire. Does anyone have any videos they recommend for both the Upstream and Downstream sensors? Plus any tips when I go to loosen the sensor from the exhaust. In the past, with other vehicles I've had, the exhaust bolts/parts can be very difficult to remove. I saw one video they recommend 7/8 split socket, to remove the sensor.

Edit: I did find a good video on the downstream with the 3rd Sensor (see link below). However the Upstream will be a lot more to it. Let me know if any of you find a good video on the Upstream Sensor removal.