well yeah that would more than likely be the issue. I have tried all different fuel stations thinking it was sh*t fuel. but mind you its hot up here atm. I have just knocked it back to the 9psi tune and holding out till I can get time off work to go back to the tuner.

but nobody knows how to retard it with the x cal3?? (tuners)

if your car is still pinging change the plugs, im surprised nobody has said this yet. When running a flash or custom tune, u need to gap your plugs. Pick up a good set of ngk or typhoon plugs from ford and gap them to I think its around 0.75 to 0.8 and u should be right with the pinging

Engine missfiring is generally because of plug gap. I'd say to much timing or boost!

I hate the sound...Always best described as hitting the top of the piston with a hammer. Doubt very much that its your plugs causing the ping as they usually cause spluttering under load if the gaps too big. Take it back and get it soughted properly.