i have a 04 MCS with dominator cam, 15% reduction pulley, 550 injectors tuned by rmw. i have a longer than usual cranking to fire it up also runs a bit rough at idle and misfires slightly. Drives fine until coming to a stop then its rough and misfires. While looking on the obd scanner i noticed with the ignition on engine off the tmap was at a certain number ( lets say 1735 i cantv remember exactly) and the map sensor value on scanner was jumping from 1700-1800. am i right to say i have a bad map sensor ?

 

Sounds like it, or its TMAP twin. In case it helps, from Bentley's MINI Cooper / Cooper S 2002-06 Diagnosis without Guesswork:



TMAP and MAP Sensors (Cooper S) p. 13-118

TMAP and MAP Sensors (Cooper S) p. 13-119

TMAP and MAP Sensors (Cooper S) p. 13-120

TMAP and MAP Sensors (Cooper S) p. 13-121

 

Do you have an afr guage and have you checked if your car is running perhaps on the rich side due to the tune and the 550 injectors ? Afr guage may help to point you as to what is happening during the bogging .