when boost starts coming in, its pop bangs and holds back like its misfiring.

Could this be coil packs.?

Also sometimes when driving normally the check light comes on. ECU reset and nothing, and all is well.

 

i would say coil packs an spark plugs mate i had the same problem as soon as i hit high boost it was back firing so i took them out an had a look an they was all cracked as soon as i changed them the car run perfect but before you get the coil pack just look an see if they are cracked if they aint then just try a set of new plugs an set then gap to 0.65

 

Yeah agreed, plugs or packs breaking down