R32 Gtr Running Abit Rough

[rb180]

My gtr sounds like its mis firing/ choking sometimes. It happens sometimes when taking off and even when cruising. For example cruising at 60 kms and the accelerator is held enough to keep the speed to a constant 60kms and you can hear the car cutting out or sort of chocking abit in the exhaust note. When the car is idling you can hear it cutting out abit also. This only started happening since i put new front/dump pipes and high flow cat on a few days ago. The funny thing is that when i accelerate hard and it hits boost, its smooth and doesnt seem to cut out at all. Only just before it hits boost and pretty much when holding the accelerator at a constant rate it seems to happen. I thought it might be a loose afm plug so i made sure they were on properly.

Also sometimes it just runs fine and this doesnt happen at all?

So im not sure what it could be?

Any help would be great guys.

Cheers