[reedjasonf]

I posted on this forum for the same problem but now I have a few more details.

The problem I'm having is with my 2002 Mercury Sable DOHC. The engine light is illuminated and I had the codes read. I get misfire on cylinder 4, TPS does not match MAP sensor, and TPS low voltage. The TPS has been replaced (twice) so I'm confident the TPS sensor itself is not the problem. However, I tested the voltage on the sensor by backprobing the connector. Here's what I got:

The reference voltage was 5 volts (normal according to my manual)
The signal voltage was about 0.37 with throttle closed. I had a friend open the throttle gradually but the voltage didn't budge at all. I know this is the problem now but what would cause this?

Also, my manual says the signal voltage should be under 1 volt when the throttle is closed but should it be closer to 1 v than 0.37? Please give me a reference where I can see any information you give if you can.