I Don't know if theres a way I can get those Timing covers off now, I suspect Ill have to buy new ones and break the current ones to get them off!?.
I looked over the receipt of the Tune by the previous owner and the Tuners wrote that the AFM was dirty and needed cleaning, maybe its buggered?. If Subaru is like Nissan a faulty AFM will not show up as an error code, the cheapest AFM's I can see are on Ebay at $169.00( Genuine)
GENUINE Impreza Forester Liberty wrx gt sti MAF air flow meter afm 22680-AA310 | eBay