LSA missing/hesitation

[Eldest23]

Hi guys
Seem to get a slight miss or hesitation while under load in the car and when going from one gear to the next it seems to hesitate when the throttle is re-applied.
Any help greatly appreciated

[Eldest23]

yeah it is modified and all the stuff is brand new have looked at the leads and plugs but can't see anything obvious.

[Eldest23]

I use the high octane fuel but still have the same issue.