I have now replaced the speedometer sensor for the 4th time in the last 4 months. Car runs terrible and speedometer stops working. Found the part on Amazon for $20 new. After 2 weeks, same problem. Got another one, 2 weeks later same problem. After the 3rd one went bad I found one on EBay, stated it was original equipment genuine Toyota part $25. 2 weeks later I have the same problem. Speedometer stops working and hardly runs. I should also state that I had an oil leak, replaced valve cover gasket and camshaft bore plug that leaked oil onto the sensor. I also replaced the sensor connector plug thinking that the oil leak may have caused the problem. Any ideas why it seems the sensor goes bad after a week or two, cheap part ? Advance Auto, AutoZone, and O'Reileys want $140 for the sensor. Could it be another problem ? Car runs great for a week or two after I replace the sensor although it's my wife's car and she only drives it 20-30 miles a week. Car has 120,000 on odometer . It's been a great car, she loves it.