Help!

Please help.

I have a problem with my 2002 Octavia vRS. It's been to the dealer several times now but they can't seem to resolve it.

At full throttle, in all gears, it seems to develop what can only be described as a misfire, it's not a misfire but it feels like it, it seems to go on and off boost momentarily, especially as you get higher up the rev range (4500 rpm upwards).

The dealer originally diagnosed it as being a faulty lambda probe and reset it but the fault came back. Eventually they replaced the lambda probe which again cured the problem but only temporarily. It's come back again and it's driving me mad.

Has anyone else experienced this? Did you manage to cure it? If so, how? If anyone has any thoughts I would be extremely grateful.

Thanks,

Andrew