Yep, it's most likely your car's way of saying "That's about all the aftermarket parts I can handle before I'll need to be professionally tuned." Try giving your ECU a few days to re-learn what it needs to in order to run with your current setup and you'll probably be ok. I ran my car with an OTS Cobb Stage 2 map and GrimmSpeed modified headers w/ high flow crosspipe and a Turbo XS TMIC for a short period of time before getting protuned and I noticed similar symptoms when I really mashed the gas.
07 WRX (Albins 5MT + Blouch 20G)
Jorge Carrillo Tuned (365 whp/340 wtq)