I've Got A Octavia 1.9 Tdi 2001. Recently I Was Traveling From My Girlfriends In Se London When Suddenly I Lost Alot Of Power. It Was Just As Though My Turbo Stopped Working. I've Got A Tuning Box Fitted Which Pushes It Up From 110bhp To 135bhp And I Must Say What A Big Difference It Makes. So My Question Is Does Anyone Know What Caused My Turbo To Stop Working?

You would need the car plugging into a diagnostic computer to see what fault codes have been logged.

Some tuning boxes can occasionally cause the car to go into limp mode.

Also I've seen mention of the vanes on the turbo sticking (clogged up with soot) and the same thing happening.

Those are two common causes , but there are plenty of other things that could be at fault.

Stopping the engine and restarting will get it out of limp mode but if it happens again try running without the tuning box for a while and see if that cures it.

hi. and welcome. do a search for vagcom owners in your area. and ask them for help.

Welcome to Briskoda