I have a 01 V92C. I put aftermarket drag pipes on it and a generic tune on the Power Commander. When I started it up, it was popping a little and backfiring occasionally (guessing due to it needing fine tuned) took it for a quick spin and it stalled out when down shifting. When I tried to start it back up, I got a check engine warning. I also got a "5 33E" code. Does anyone have any ideas what that code means and what caused it?