I just drilled out a 1.5 inch hole through the middle of my stock cat converter to give me some boost till my high flow cat comes...

The check engine light is now on... Im guessing this is just to tell me the exhaust isnt clean or is it a more serious problem?

Also would it benefit me at all to make the hole 2" like the rest of the exhaust and maybe put a pipe down the middle to completely bypass the cat?