2000 Avalon VSC & VSC OFF LIGHT

VSC & VSC off light are on along with check engine light . Autozone said I had code P0171 which is o2 sensor. What does one have to do with other and does ABS have a role in any of this?

Thanks!

I bought my 2000 Avalon XLS in Feb 2000 and this same problem started later the same year. At that time, no one had a clue what to do except tighten the gas cap and reset the processor. Since then, we've eliminated moisture, cold, unequal tire pressure, and MFS. Personally, I believe it's a grounding problem with the processor (one alarm trips and ground bounce trips the others). Sometimes it has to be reset, other times it goes away on its own. The most upsetting thing is that Toyota denies any knowledge of this widely occurring problem and the troubleshooting process is too involved for a dealer to perform. I was glad to see that they finally fixed that annoying reflection of the dashboard lights off of the front windshield. Ugly as it as, I had to tape a piece of cardboard to my elegant dashboard so I could see the road at night. Oh, by the way, I tested the VSC on a wet parking lot and when the VSC light and ABS lights come on, the actual systems aren't working! Fortunately, I have not been in a situation where loss of ABS and VSC mattered much, but when you pay so much for a "safety" feature, it had better damn well work!