idle issue's

[Anto Modded]

I put a janspeed manifold on and a ashley back cat system on and a induction kit. It ticks over fine most of the time but sometimes its like it is going to cut out. Is this normal or how can i stop it

 

[Demarest]

Normal i believe, cars a few of my mates have with either larger bore exahausts and induction kits or both some times feel as if they are going to cut out when idling., mine with just a K&n direct on the throttle body, sometimes feels like it will cut out in colder weather