I have an 05 wrx with a full turboback exhaust. It has a catless up pipe and a catless down pipe. I have a spacer on my O2 sensor so I don't have any CELS. I mainly did this because of emissions. I was considering removing the spacer when I install my accessport. Just wondering if anyone else has done this and would it hurt to leave the spacer on? Being that The only cat I have is the small one in the aftermarket exhaust behind the O2 sensor I assume it will throw a CEL and when I get it inspected I will need to replace the spacer.