$49 at autozone for a TPS.
Found this on the net. Might help you.
Throttle Position Sensor - Testing
1. Set DMM to read DC Volts.
2. Connect black COM lead probe tip to the TPS ground wire.
3. Connect red Volts lead probe tip to the TPS Reference Voltage wire.
4. Turn ignition ON. Do NOT start engine.
5. Look for a 5 volt reading - (some manufacturers may differ - verify correct
reference voltage for the specific vehicle being tested).
6. If reference voltage is too high or too low, look for a problem with the wiring harness or PCM.
7. After establishing reference voltage is O.K., connect the red Volts lead probe tip to the TPS to PCM signal return wire.
8. Look for low voltage at idle position that will smoothly increase as throttle is applied. Any fluctuation of the DMM Bar Graph or erratic voltage readout indicates a bad sensor. Verify factory specs for low voltage (idle) setting, even one tenth off can make a difference in vehicle performance. The high (full throttle) voltage should reach at least 80% of the reference voltage.
9. Turn ignition OFF when test is complete.
1997 Pontiac Bonneville SEi-SCRAPYARD
2000 Chevrolet Blazer LT 4X4 4.3L
2002 Chevrolet *-10 LS Ext Cab 4X4 5.7 V8