Pointless doing a scan on an AGU as nothing ever shows up. Better to do it the old fashioned way.
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Doing it when hot, I would say fuelling rather than spark.
1. Whip the plugs out and see what they look like.
2. Clean the throttle body, if it hunts for idle even remotely.
3. Use some injector cleaner, and give it a run.
4. Unplug the MAF and try to replicate the problem. It may run worse, but if it stops the cutting out it's a fault with the ECU diddling with fuel trims, not necessarily a duff MAF.
5. Check for air leaks.
If you know someone with a copy of VAGCOM do a log of the air flow values.
