[ShoCk_]

Something very strange is happening to my car.

When ever I put my foot down the car launches itself forward as the boost kicks in at 2-2.5rpm

But for some reason it doesn't do this as aggressively anymore, it's lagging. There seems to be boost when i'm at 70-80mph though so higher up in the rev range it feels normal.

I recently had a brand new alternator & battery installed. Car has also had a full service.

No fault codes, or errors.

Bad batch of fuel ? are there any additives / potions I can feed the car to clean up it's insides ?

I do a lot of regular in town driving and rarely go on the motorway.

Car is Stage 2 with the DPF gutted by Avon Tuning in Bristol.