Where to start on a rough running 2010 VW EOS?

In this video Anthony is presented with a rough running 2010 VW EOS. A previous workshop had already fitted new spark plugs and replaced the Oxygen sensor. Multiple fault codes present including: • P2279 Leak in air intake system • P0300 Multiple cylinder miss fires • P0301 Cylinder 1 missfire • P0302 Cylinder 2 missfire • P0303 Cylinder 3 missfire • P0304 Cylinder 4 missfire • P0506 Idle control system • P0171 Fuel trim too lean TaT members can read the Repair solution at www.tat.net.au/tatsafact/4039