hello there when starting the car it sometimes cuts straight away to get over this i have to put my foot down which is not a good idea from cold. when driving the car and i take my foot off the pedal it drops to around 900 revs and then drop drastically but pick up again straight away like its about to stop but it never does. a new maf ( mass airflow sensor ) has been fitted but it has made no difference. no error codes are coming up. any help would be appreciated thanks patch.