Hi

Does anyone know how I can test my MAF sensor - I don't have access to another to try it.

It's on an X Reg Impreza Turbo (00).

Cheers Bud

 

They are not that easy to test, you need a digital volt meter, to measure the o/p voltage given, but this depends on air flow.
What makes you think it's faulty?
Try re-setting the ECU with the connectors under the dash, if the maf is faulty, the idle speed tends to be all over the place on this particular model.