I can anybody help. Had a new clutch fitted to my mk1 focus rs
And now car will not idle properly and hunts when it idling and when you floor it in 1st it backfires

Car is a phase 2 with uprated actuator and re-circ dump valve and decat mongoose and a bluefin
But never had this problem before went in for clutch

While car was in for clutch we fitted and new atmo dump vale and boost pipes new ford plugs new ford fuel filter

We have now taken off the atmo dump valve boost pipes and put it back to how it was before the clutch job and even put old plugs back in

Can anybody help please