Thanks for the tip. I thought it sounded suspicious. I went to the local dealer that I've been dealing w/ since I got the car in '96. I'm planning to replace the rear O2 ourselves (just like the front one) if it goes bad. I just need to find where that rear O2 is (maybe behind the catalytic converter?). I'm assuming it's close by the front one somewhere.

I went to another local dealer when the front one was out to get them to turn off the warning light. They told me that if I don't get it replaced ASAP, it'll ruin the whole engine. The only thing that I noticed when it went bad was my fuel economy went downhill, but that's all that I noticed.