What is the best method for checking the Throttle Position Sensor? Mine doesn't really seem to make any difference when unplugged/ plugged back in, I'm not really sure if it's supposed to though. Right now if I step on it in second around 3k or in third at all it stumbles for a second and then goes. It was also suggested to me that it might be a leaky injector? It just started doing this out of the blue, I cleaned the MAF area out today and no difference. Any advice helps, thanks.
-Jon

 

Your problem sounds like a bad coilpack,mine did about the same thing...

 

It has 2 connectors: one built- in and another - hangs on the wires. The actual TPS is the second one. Built-in connector is the Closed Position Switch. It should close contacts when throttle just fully closed.
I'd check TPS with ohmmeter without taking it off the car - just unplug the TPS connector. It should produce smooth resistance change through the whole range between middle contact and each of the side contacts. If you notice any glitches in resistance while you manually move throttle - replace TPS. Engine should be stopped during this test.