2007keates

hi i ve been running my classic import impreza for just over a year i regular service her and she been running great with no warning on engine management but just lately its been really over fueling to the point wear its holding back then popping ang farting when i acclerate and leaving a jet stream of fuel out of the back could any one shed any light ? i will say it got blitz s spec electronic boost controller and hks FCD and hks AFR could these be playing up or effecting it in any way. many thanks john