2000 RX300 Sensor question

[Naif2]

Hi guys hoping you can help out my mom,

She has a 2000 RX300 and her check engine light keeps coming on and off from time to time, she went up the local mechanic and he said that is was the bank 1 sensor 2. She had her bank 1 sensor 1 replaced back in March. I was wondering what exactly this is and how important it is to get it replaced? Thanks for any feedback

[magellan44]

I hope some one gives you a reply, my wife's is doing the same tbing. She took it back to Lexus about 6 months ago and they charged her $500.00 to replace the sensor. I about killed her and the dealer for that one. This is the 3rd time that these sensors have been changed out.. Lexus tells me that the others were under warranty and that she has only paid for one. What kind of anwser is that. It is the same sensors that are the problem. She shouldn't have to pay.

Thanks