I have a 97 LS400. The check engine light went on the other day. I stopped by Autozone and had them plug in their scanner (free of charge). The error code was for a defective rear O2 sensor. I order a Walker universal O2 sensor from www.oxygensensors.com it cost me $50 including shipping. I jacked up the passenger front side to access the O2 sensor. I cut the lead wires from underneath the vehicle and remove the O2 sensor with the O2 sensor removal tool that you can borrow from Autozone. I installed the new O2 sensor and then soldered the 4 wires together and wrapped them with electrical tape. I just used a standard $10 soldering wand. You could use the connectors that are included with the O2 sensor, but I prefer soldering. The whole job took about 1 hour.
