Hello! I have struggled with a problem on my Octavia. I buy i cheap when the vacuum actuator on the turbo and the clutch was gone(because of the deffect vacuum actuator and sticked vanes it goes in limp all the time). I have no changed both, and cleaned the turbo really well as it was esy to unfit the exhaust when the gearbox out of the way. I adjusted the rod on the actuator the same as the old, and cheched it with a vacuum tester to the specks. But now when i drive, a few minutes after i start driving, it goes in limp mode - no power. Start and stopps an it goes like h... and i can drive all day without problems. One special place, a shop where i do my groceries, i start from there and in to a tunnel and almost at the same place 50-60m innside the tunnel it goes in limp - every time - pushing or just crusin with almost no power. Somtimes i also happends when driving cold in the mornong and the engie braking down a small hill... I have changed all vacuum lines, mafs and the pressure and temp sensor on the intercooler... Please - any ideas anyone?????

Have you checked it is not sticky at all (I know you cleaned it, but....)

The CTS may be faulty.... this has been known to cause odd issues.

temp sensor on the intercooler - isn't that the MAP. Can you get VAGCOM on it to log what is going on - would be good to log in the tunnel if you know is going to fail..... you might find what sensor/etc is causing the issue.

N75?

Yes, sure - not sticy at all. What is the CTS? Changed the N75 too... Has orded vag-com, hope this will help me solve the problem - when learned it... What i think is really strange is that it seems to be a time oroblem more than a boost problem, when limp a few minutes after start, start an stop and i can drive all day with no limp before stop the engine again, then limp after a few minutes - and than specially in this tunnel....

What about the egr system...??

Cleaned the egr valve tonight, much more soot in it than i realised when look at it with a flashlight. Also cleaned and lubricated the valves with crc and changed the last hoses(ok, but changed anyway). Test drive, no limp.. :-). Follow up when drove more...