A small problem i have. Fitted a full de-cat mongoose a few weeks ago and had a problem getting the old lamda sensor out from the old cat due to rounding the nut anyway i enventully gave up trying and just plugged up the threaded hole in the new de-cat with a bolt and tucked the lamda sonsor out the way for the time being! (Yes i know... rough!!) Would this cause it to run rich it being disconnected? And when i came to do it properly i realise the threaded hole in the de-cat is a good bit bigger than the lamda sensor its self????? why is this?