Today I replaced a downstream heated oxygen sensor on my 97 toyota avalon. 258k miles. Took me a few hours, trial and error.
1. Removed Passenger captains chair (only 4 bolts, and an electrical connector
2. Removed door trim pieces and seat belt plastic trim pieces.
3. Lifted up carpet to expose the connector for the downstream O2 sensor which is located vertically along the right hand side of the shifter box area. It's not on the floor...more in the corner of the floor and the middle console wall.
4. Lifted up car and broke lose the O2 sensor using a crescent wrench and rubber mallet.
5. Pulled on the grommet that encases the O2 sensor wires leading into the car. With
the grommet out, I pulled the connector out, too; so that it was all hanging down below the car.
6. Took out the old sensor, cut the connector off, clamped the connector wires to the new sensor, and re-installed. The heated O2 sensor was purchased on amazon for $30 something dollars a few months ago.
7. Put everything back in the order it was taken off, and Boom! Engine light gone.
Happy day! Can't wait to see what's next!
I tried to take video of all of this using a pair of "video camera sunglasses" I purchased off ebay some time back. Pulled out the lenses and placed over my prescription glasses. Very dorky, but it worked!....sort of. Once I figure out how to put it into a video and upload to youtube, I apologize for making any one "car sick." :P