Think about this a little bit. How does air get into your motor? It comes through the filter, the AFM, and straight into the turbo. It must then pass through the entire intercooler piping before it feeds into the throttle body. If your AFM senses a certain amount of air, and half of that escapes before reaching the throttle body, You will have way too much fuel for the remaining air, causing a flooding effect.
Cracks in IC piping can be hard to see. Do a search on a boost leak detector. You can build one for $7-8 and pressurize the system with a compressor.