159 2.4 JTDM feeling "stifled"
My 2.4 JTDM 159 has started to feel more and more "strangled" recently - lacks power at low revs, then when the turn it kicks in its sudden then it pulls ok but not as well as it used to - It feels like a big turbo lag. Sometimes when i floor it at lower revs it stutters slightly too - but this doesnt happen when accelerating gently.
The car has DPF removed and EGR deleted and the Alfatune remap - the intake has been removed and cleaned and swirl flaps are operating as they should be.
The air filter looks clean although it hasn't been changed for approaching a year now, MAF sensor recently failed but has been replaced. The car just generally feels more stifled than it used to.
Can anyone offer me any advice?
Thanks in advance