recently changed my gearbox on my95 wrx jdm turbo import,
started the car up and now has a bad backfire.it also has trouble starting.
also a little loss of power, i have tryed cleaning the plugs and checking boost pipes but still the same issue.also the car will stall after a little while if i let the car tick over.any ideas on what it could do people as want my car back up and running now

 

any ideas people as bugging me now