Big pop and a bang after to much boost is usually the ecu cutting off the boost. Be sure to check the vaccuum hose that goes to the underside of the ecu. Take the heater out of the bay to see it. The can sometimes wiggle their way under the heater and get squashed!

Ditch the incar boost controller as well, nothing but problems them things. Changing the boost on a daily basis causes nothing but problems. get it set up to a comfortable ammount, then if you are not ragging the car, just use half the throttle. lol

Get it to tuners asap. MFI is a nightmare on the rollers, let alone on the driveway!