I have a 1.8t aum with a R-teck remap, which does not feel as quick as it used too. I have changed pretty much all the usual stuff, like air filter to a pipercross panel, new coil packs, new maf, new N75, changed the diverter valve to a forge 007, replaced breather hoses and others with silicone ones, have a new silicone tip, new 02 censors. Recently had a service which also included a new fuel filter, and replacement thermostat, and a repair to the air pump changing the rivets to bolts.
All this, and a few other things done to it (that would not effect power like new bushes and discs and pads) over the past year which have cleared the infamous 17705 code, (which I have been free of for some time now

) but there is certainly a lack of power still

It is a bit better than stock, but not what it used to feel like when the remap was running good. I have no codes coming up on my code reader, so I am at a loss to think what the lack of power could be. Sometimes it feels like some of the power comes back every other day, not full power, but an improvement nonetheless, but that magical remap spark seems to of gone!
I have heard that a new stainless steal exhaust like a miltek may help, but as there are no leaks in the exhaust, is it necessary to change to get the power back?
Does anyone have any suggestions as to things that could be causing the lack of remap power? Could the injectors need changing? Any suggestions I would be grateful of, thanks.