Probably because when you mess with intakes.. it changes how the MAF sensor reads (hz). Therefore, a quick run around the block... would not be a good test. Disconnect battery for like 15 minutes (to reset LTFT's) and then run it for an extended period of time. This will allow the PCM to learn its fuel trims which in turn works with the MAF.
Temperature does affect it... however... I dont think it the reason you feel that.