Seems that when I slow down (ie, let my foot off the pedal completely) my car acts funny and shows an SES light. My car will also surges at idle and sometimes dies at idle. I pulled a code 22, Throttle Position Sensor. I got under there tonight with a DVOM and gray wire to ground shows a steady 5v going into the TPS. Then I tested dark blue to ground, the return signal wire and got some interesting results. With the throttle closed, it gave a really funky reading. Sometimes it was 0.0V, and sometimes it was around 250mV, and nothing was ever really steady. It basically looked like the voltage reading that you get when your DVOM isnt touching anything. Now as soon as I started opening the throttle, it gave normal results. Voltage gradually went up towards 4-5 volts as I got closer to WOT. Going back down from WOT gave what still seemed like normal results, voltage slowly dropped back down, but as soon as the throttle closes completely (it only does it when its COMPLETELY closed, slightly open gives regular reading) it starts giving the weird reading again.

Are these signs of a bad TPS, or could it somehow be just out of adjustment? Searching got me this far, but now I need to figure out if these signs mean its bad or not. I know my computer is out of whack and in dire need of a proper tune, and I fear that the computer may be causing the surging because its current state of confusion and throwing false codes.

 

Bad TPS. Replace it.