2000 4 cyl OBW, auto trans. I need to replace the front O2 sensor. What is the best approach? In other words, do I remove the front passenger side wheel and approach from the side, or approach from the front? Don't have a lift, so I will be doing this in the driveway with ramps and jack stands. TIA.

Last summer I replaced the 02 sensor on my 99 OBW. I used plastic ramps, and drove up on the ramps with the front wheels. I chocked the rear wheels, and applied the parking brake. I didn't see any need for jack stands, since the wheels were well chocked.

 

Suggest the first thing to do, is to spray the 02 sensor with PB blaster, then wait a couple of days for the PB to loosen up the rusty crud sensor threads. Otherwise, you may have a hell of a time getting the sensor loose. I had to buy a special offset socket for my 3/8 drive to fit over the sensor for removal, as the sensor is in an awkward angle to get a socket on. I slid a 2 foot bar over the end of my drive for added leverage. Still, it is a bear to get the old sensor to loosen up. Once removed, it is easy to install a new sensor.

I'm following a couple of threads about O2 sensors, and other things I have seen mentioned are a) warm things a little bit by running the car a few minutes (but avoid burning yourself with the cat!), and holding the welded flange where the O2 sensor is mounted to avoid breaking it from the exhaust when applying force to the sensor

HEAT will make it much easier to remove. Warm up the exhaust system by running the engine for 10 minutes or so. Wear long sleeves and heavy gloves. This can be done from above if you remove the air intake tubing. It helps to be able to smack the end of the wrench with a big hammer though.