I have an 03 WRX with PPP I fitted a slip jointed heat wrapped up pipe and a prodrive cat down pipe today. The exhaust gas temp sensor was completely removed when doing this. I started it an ran it for a while and had no cel at all. Is this normal when disconnecting this sensor. I have since disabled P0546 cel with my tactrix cable so hopefully all should be ok until I get a remap. I also have a de-resonated centre section so noticed it a little louder with the occasional pops on the over run. Is this to be expected with this cat in place.
With just this cat in place will I need it very hot for MOT or will it be fine.

Thanks