[mohrds]

I'd pull the ECU codes and see what it said. Mine did that and it was a TPS.

1)Remove the kick panel just beside the left foot rest on the driver's side.
2) Locate blue wires.
3) Locate black connector. Hold it notch up.
4) With ignition off, insert one of the wires into top row, 2nd pin from left.
5) Turn key to on position, but do not start the car.
6) Watch blinky check engine light on dashboard. Count blinks. Long blinks = 10, Short blinks = 1.
7) Keep watching blinky light until you get mesmorized.

To clear codes (after problem has been resolved):

1) With engine off, stick the blue wires to 1st and 2nd pin in the top row counting from left on the black connector, with notch facing up.
2) Start car. Shut off car. Remove pins.
3) Read codes to make sure they are clear. No codes = steady blinks at 1/4 second intervals.

CODE PROBABLE CAUSE
11 Crank Angle Sensor or Circuit
12 Starter Switch or Circuit
13 Cam Position Sensor or Circuit (TDC Sensor on Justy)
14 Fuel Injector No. 1 (Legacy, Impreza, Justy, SVX)
14 Fuel Injector No. 1 and 2 (XT, Loyale, GL, DL)
15 Fuel Injector No. 2 (Legacy, Impreza, Justy, SVX)
15 Fuel Injector No. 3 and 4 (Loyale, GL, DL)
15 Fuel Injector No. 5 and 6 (XT-6)
16 Fuel Injector No. 3 (Legacy, Impreza, Justy, SVX)
16 Fuel Injector No. 3 and 4 (XT)
17 Fuel Injector No. 4 (Legacy, Impreza, SVX)
17 Fuel injector No. 1 and 2 (XT-6)
18 Fuel Injector No. 5 (SVX)
19 Fuel Injector No. 6 (SVX)
21 Coolant Temperature Sensor or Circuit
22 Knock Sensor or Circuit (Right Side on SVX)
23 Air Flow Meter or Circuit (Exc. Justy)
23 Pressure Sensor (Justy)
24 Air Control Valve or Circuit (Exc. Justy)
24 Idle Speed Control Solenoid Valve (Justy)
25 Fuel injector No. 3 and 4 (XT-6)
26 Air Temperature Sensor (Justy)
28 Knock Sensor No. 2 (SVX, Left Side)
29 Crank Angle Sensor (SVX, No. 2)
31 Throttle Position Sensor or Circuit
32 Oxygen Sensor or Circuit (No. 1, Right Side, On SVX)
33 Vehicle Speed Sensor (VSS) or Circuit
34 EGR Solenoid or Circuit
35 Purge Control Solenoid or Circuit
36 Air Suction Solenoid Valve (Impreza)
36 Ignitor Circuit (Justy)
37 Oxygen Sensor (No. 2, Left Side, On SVX)
38 Engine Torque Control (SVX)
41 Air/Fuel Adaptive Control
42 Idle Switch or Circuit
43 Throttle Switch (Justy)
44 Wastegate Duty Solenoid (Turbo Models)
45 Pressure Sensor Duty Solenoid (Turbo Models)
45 Atmospheric Pressure Sensor or Circuit (Non- Turbo Models) 49 Airflow Sensor
51 Neutral Switch (Manual Transmission Models)
51 Inhibitor Switch (Automatic Transmission Models)
52 Parking Brake Switch (Exc. Justy)
52 Clutch Switch (Justy)
55 EGR Temperature Sensor or Circuit
56 EGR System
61 Parking Brake Switch (Loyale)
61 Fuel Tank Pressure Control Solenoid (Impreza)
62 Fuel Temperature Sensor (Impreza)
62 Electric Load Signal (Justy)
63 Fuel Tank Pressure Sensor (Impreza)
63 Blower Fan Switch (Justy)
65 Vacuum Pressure Sensor

To perform the TCU self diag test for EXISTING problems
1) Warm up engine by driving at speeds greater than 12mph.
2) Stop vehicle and turn ignition switch OFF.
3) Turn ignition switch ON and make sure POWER indicator lamp comes on.
4) Turn ignition switch OFF.
5) Move selector lever to D and turn manual switch ON.
6) Turn ignition switch ON.
7) Move selector lever to "3" and turn manual switch OFF.
8) Move selector level to "2" and turn manual switch ON.
9) Move selector lever to "1" and turn manual switch OFF.
10) Partially depress accelerator pedal (to turn idle switch off).
11) Check code as displayed on POWER light. Blinking once every 1/4sec is normal.

To perform the TCU self diag test for PREVIOUS problems
1) Warm up engine by driving at speeds greater than 12mph.
2) Stop vehicle and turn ignition switch OFF.
3) Turn ignition switch ON and make sure POWER indicator lamp comes on.
4) Turn ignition switch OFF.
5) Move selector lever to "1" and turn manual switch ON.
6) Turn ignition switch ON.
7) Move selector lever to "2" and turn manual switch OFF.
8) Move selector lever to "3" and turn manual switch ON.
9) Move selector lever to "D" and trun manual switch OFF.
10) Partially depress accelerator pedal (to turn idle switch off).
11) Check code as displayed on POWER light. Blinking once every 1/4sec is normal.

Trouble codes:
11 Duty solenoid A
12 Duty solenoid B
13 Shift solenoid 3
14 Shift solenoid 2
15 Shift solenoid 1
21 ATF temp sensor
22 Atmospheric sensor
23 Engine revolution signal
24 Duty solenoid C
25 Engine torque control signal
31 Throttle sensor
32 Vehicle speed sensor 1
33 Vehicle speed sensor 2