ashley 4 2 1 manifold lambda question

[Danknight72]

have fitted a ashley 4 2 1 manifold and janspeed mid pipe and back box , my car being a pre face has a pre cat lambda which ive now relocated to under the engine to where the boss is on the ashley manifold (just behind the sump ) , ive extended the wires and wondered if this will affect the running as got a mid range hesitation and fast idle , ive got a group a air box fitted as well