codes 17566 map sensor implausible signal,17961 barometric /mapsensor implausible relation and 17912 intake air system leak detected come up at random [approx twice in 10 mile roadtest] previous to this cambelt tensioner collapsed,head off,valves taken out and checked because some kissed piston none bent [so i,m told,] i didnt do engine repair but car seems to run ok and valve timing has been checked since and is ok.launch x431 diagnostic tool allows me to look at map sensor output whilst on road test and when engine management light comes on trace doesnt seem to do anything silly,not sure how to go about this one,done the obvious like checked wiring not rubbing etc.Anyone either had this problem or has suggestions on verifying map sensor output is ok I would be very grateful.