Will I be able to pass the emission with my pre-cat gone? And does it void my warranty if I have it out?

 

Well, it voids the warranty on the pre-cat.

If its the pre-cat that you'll pull with a y-pipe replacement...it should pass emissions if the car is warmed up...when the engine is cold, it would probably fail...just drive around the block a few times before the test.

 

I have Cali-spec. And I gutted out the comb looking thing inside the pre-cat that comes from the headers

 

as long as you have the main cat, things should be good