I’m looking to buy. BMW 1 series 114i 62 plate for my first car. It seems to be good, passed HPI check has recently got a new timing chain as it’s got 96k on the clock. It failed it’s MOT with a (Exhaust carbon monoxide content after 2nd fast idle exceeds manufacturer's specified limits) but then got a passed the same day. Should I trust that this is fixed? and would the problem occur again? If so how much would this cost to repair.