I got a good aftermarket MAf a year ago. I had similar problems to you for £21 and you can send it back if it is not the problem for a small restock fee.
The have a good reputation but I got it via ebay.
[URL unfurl="true"]https://www.ebay.co.uk/itm/MASS-AIR-FLOW-METER-SENSOR-NISSAN-MICRA-MK2-K11-1-0-1-3-1-4-0280218040-/303179834376?hash=item4696ed2408[/URL]
