catalytic converter

Had a Mini R56 for a year now and recently upgraded it's catalytic convertor due to an MOT fail. However, since then it juddered and struggled to gain speed for a moment, before being okay. The engine light flashed sometimes and the P0420 error showed as a cat convertor issue. However, I...

Hello, I've had a P00420 code thrown up by the car - an R56 Mini One 2007 (2/2) - and so I took it to the garage for an MOT to see exactly whats wrong. I was told I need a new cat and two new sensors. The car failed on emissions and the sheet is attached. With this info can anyone tell me...