was driving last night about 40mph, the ecu light came on for about 10 secs and then wen offf again, continued to drive it then 5 mins later,, at 40mph-ish  the car cut out as if the ignition had been turned off, so i put it i N and pulled over to side of road. started the car again and it was a bit spluttery then ran fine, drove it again for anouther 5 mins and it cut out again, again pulled over and when tried to start it this time, it just cranked and spluttered. waited a min and tried starting it again and it started no problem, managed to drive it 25 miles home and its been ok. i paperclipped it today and got these codes
144 No immobiliser signal recived Faulty unit or break in wiring
73 Air Flow Sensor (AFS) Low voltage
31 Engine RPM signal (crankshaft sensor) No signal

i recon i can ignore 144 and 31, but 73 may be the problem ?
i discinnected the air flow sensor today and started the car and it runs fine but ecu light stays on, reconnect it and no light. just wondering if i need to replace it, and would this cause it to cut out ? as it runs when its disconnected ?
just dont want to get stranded anywhere.

Unplug the MAF as a test, the car should run (albeit not to perfection). If so, then replace the MAF.

If it still cuts out, things to be suspicious of are crank sensor, ICV (only at idle) and EGR.