'99 LX470 with 170K on it. Whenever I press the accelerator - in park or in motion - I hear a buzzing noise that sounds like it's coming from behind the dash. It's tied directly to pressing the accelerator, not speed or anything else. It goes away immediately when I take my foot off the accelerator. Any ideas? I thought maybe tach but I can be going 60 and decelerate by taking my foot off the gas and it goes away then, too, until I press the accelerator again and the buzzing will start and continue until i let up on the pedal. Thanks.