Did you disconnect your battery while you were working on the car? If so, your ECU might have been reset and it might have to relearn a few parameters before it functions completely normally again. I had similar symptoms right after I cleaned/oiled my air filter and reset my ECU with my Cobb AP, except my car actually stalled when it sat there idling unless I gave it a little gas. After driving it for a couple of minutes though, everything went back to normal. Try giving it a day or so and see what happens.
07 WRX (Albins 5MT + Blouch 20G)
Jorge Carrillo Tuned (365 whp/340 wtq)