I had that one mate and found it to be the green one lol. I think one is with blue cabling and one green and it was the green one that was fucked but can't remember where it was. Have a look and see which one it is. P0133 was the fault code on mine too.

I cant remember right now but I have a slight feeling it's post cat as the blue one I remember being pre cat although I'll check in a little while to make sure.