Finally get my S-AFC on my MY00 Legacy. Everything works good, except when the engine is on, the throttle % reading on S-AFC is unstable. I checked the sensor voltage reading. It looks like it's not getting stable power to get correct reading. The strange thing is, when the engine shuts off with ignition key on, the reading is 100% accurate.
I checked the ground wiring and rewired 2 ground wires and the wire for throttle %, but didn't change a thing.
I also checked the settings, In 5 out 5, cylinder 4, throttle arrow points northeast.
could it be a bad TPS sensor or just my bad wiring skill? I use walmart type splicers and swapped them when I rewired the 3 wires. Any input?