These were not very well-thought-out modifications. The side airbags are part of the system- If they're out of the car, the light will illuminate unless you change out the module for one that's not expecting side airbags. You've also just endangered yourself more in the event of a side impact collision.
The gutted (pre?)cats will cause a CEL because of the lower O2 sensors. You'll need a set of (2) MIL Eliminators from Marty at MSDS or you can make them yourself. There is a how-to somewhere on the boards, I would recommend searching.