I have a couple of problems with my 2008 Octavia 1.9 TDI 105 BHP estate which i could do with some advice please . I bought the car at three years old from  auction andI believe it was a Skoda management car. The aircon has never blown cold so last year I had it regassed at a local non franchised garage. The mechanic said there was no sign of leaks or damage and it held vaccum for ten minutes before the regass. Within three days it was not blowing cold and when I took it back the garage were not interested. So this week I took it to a franchised garage  and they checked/for visible leaks and  damage to no gain and pressurised the system with nitrogen containing an ultraviolet marker dye. Once again no visible leaks or damage, pressure maintained and they kindly re-gassed for free, the gas apparently contains amongst other things a green marker dye and no leaks have been evident. Within two days it had stopped blowing cold and my own mechanic states it must be the A/C condenser behind the glove box where the leak is? Apparently there are two on the Skoda the main one being in the front of the radiator? The second issue is loss of acceleration through the gears under load, gave it a run on the motorway and it wouldn't go over 80 mph. The coding  indicated a faulty heater plug on cylinder 1 and an intermittent fault on the inlet manifold sensor (both changed) I took it for another spin on the motorway and it felt worse? My mechanic said it must be mechanical issue as they were no fault codes coming up so he he went exploring and found throttle body and EGR valve thick with carbon which he chipped off. The car is running a liitle bit better but still not A1, mechanic states the turbo charger is likely carboned up hence the lack of performance? Any advice would be welcome as I am considering the Mr Muscle scenario or  a turbo cleaner additive or cleaner such as Forte, Archoil, Innotec etc  or do i need to have it completely stripped down and manually cleaned?

Change your fuel filter, my car felt like I was driving with the brakes on when I got it. Even though the service history was up to date the fuel filter was filthy and the car was strangled. Easiest fix I ever did, apparently its common fir them to get clogged with an oily black film. Search my posts you will find a rather descriptive photo.

I would also 2nd the thoughts on the variable vanes being jammed....although on my 1.9, some years back, the EML light came on as soon as I hit 3000rpm

Thanks for the replies gents. The car has done 103,000 miles and has recently had a full service including new fuel filter. There have been no warning lights illuminated or limp mode re these problems and Mike I live in Cleckheaton and will try and pm Simbo for a second opinion as I don't really want to get rid of the car at this stage and would prefer a fix.