volkswagen passat dodgy turbo

[Stinkerbell]

I have a 1999 vw passat which was re-mapped last year, over the last couple of weeks the turbo has been slow to respond. if i accelerate slowly its ok, jerks a little from 2nd gear but not too bad. if i put my foot down to overtake for example the turbo takes ages to cut in and the car is jerking like mad, feels like it's going to stall. I've replaced fuel filter and plugs and checked boost pressure control valve (ok), slight improvement but still not perfect, any suggestions?

[TWR]

Hi, Have you noticed black smoke coming from the rear of the car? Can you hear a whistle coming from the Turbo area? If yes check the turbo connecting pipes,clips, cracks, oil loss.

[Stinkerbell]

Thanx.
There was one day when it was chucking out black smoke but it hasn't done that since. No whistle, have checked all pipes, clips etc. This is what is frustrating me-there's no obvious problem.

[TWR]

Hi, you say remapped? I presume you mean recoded if that is the case has it been done correct? was it done through a laptop via the Plug beneath the bonnet? if the car was running well before the remap, the problem lies there.

[Stinkerbell]

it was recoded by custom codes so, yes, nit was done correctly. it was done at gti international last year and has been fine until about a month ago. I've even taken the car to storm developments and even they can't figure it out.