my guess is you overloaded something.
check out all the fuses and relays.
also, inspect the wiring on your alpine HU. if they spliced in and something touched bare metal (a hu wire) it might have caused an overload.
Also, you just cleaned your CAI
filter, did you make sure to install it all properly? Got a CEL?
You might have something installed wrong, and the car bogged down and stalled out