This is re: a '97 GT-2.0L gas 4 cyl. I have replaced throttle postion sensors before, and I know what they do. I don't know what makes them go bad. My wife's Jetta needs one-to the tune of $163 at the local parts house! Can these things be cleaned up to make the work properly again? This car is her beat up go to work car, I hate to spend $160 on such a part. The last one that I put on my Taurus was $30+/-. Seth