Lexus Repair: 1999 RX 300 Air Flow Sensor, mass air flow sensor, air flow sensor

Question
Hello! I passed by this website and saw that people recieved lots of advice from professionals. I just had my 99 RX 300 serviced for new tires and oil change. I also got new front breaks. I mentioned to the mechanic that i have a light with check and and engine under it. I keeps going on and off for about 3 months so far. He runs some diagnostics and looks up a code in a book. He told me that I needed an Air Flow Sensor. Can you give me some background of what it is? My car had the light on and it was running fine. He also said that it was a special part and he has to order it off of a lexus dealership. I have no idea how much these things cost. If you can give me some advice, it would be greatly appreciated.

Answer
Hello, A mass air flow sensor senses the amount of air that is being drawn in to the engine so that the computer knows how much fuel to give the engine. These do go bad but I am not sure of the price off hand (Sunday morning and dealer is closed). I think they are about $200. Your car can still be running ok but it may not for long. You will also not get through emissions testing if you are required to.