hi my 2000 plate brava i.6 has failed the mot on a high lambda reading.any ideas? the cas is recently serviced new plugs oil filters set of leads etc.wondering if it could be connected to a problem i have when starting from cold on a morning.the car lacks powerfeels like its misfiring also the engine management light comes on but goes of again when you back off the throttle.once its warm all seems ok..been advised it may be the lambda sensor..but dont want to pay out for one untill 100% sure..any ideas??

get an universal lambda probe much cheaper and works just as well.
my bet is on the lambda sensor.