Vauxhall ADAM Mass Air Flow Sensor (MAF) Problems

just failed mot on emmissions because it misfires on idle, car runs fine though. Checked hoses and sprayed carb cleaner No engine management light on. Did paper clip test showed various codes i.e Maf unit, airflow sensor, o2 sensor,coolan...

Car cuts out when driving, engine light comes on but no fault recorded on diagnostics. Crank sensor has been replaced already.

When car engine is running but is idol for example in traffic or at lights for longer than a few minutes the engine begins to shudder and service warning light appears. However, if I tap the accelerator, the car seems to run normally again ...