Hi all I have a issue with my octavia it's going in to limp mode now and again I've had it on diagnostic computer and it comes up with 16618 fault p0234 something to do with over-boost has anybody had this issue I've read its possible 1 of t 3 factors ether the n75 - g31 - or faulty turbo to which I don't think it is or maybe even a split pipe but is this a common fault can anyone help me please thanks

Could be just be just sticky turbo vanes due to carbon built up. try some turbo cleaners such as archoil which you add to your fuel tank or more direct cleaners that involve spraying into the turbo