Ok, I am wanting to get my exhaust modified from the straight pipe I have now, which is about a 1.5-2 inch pipe from the resonator back to a 3.5-4 inch pipe from the cats back. If I did that by cutting right in front of the cats, removing the O2 Sensors, would it be detrimental to my car? or would it just show up as a light on the dash? I have a 2009 Lexus IS250 AWD. As of now the resonator and the mufflers are deleted.