Kurbite

So, I´m just dying to know what might be the problem AND if I am making damage driving it. So, as short story as I can - Its a Skoda Octavia 1.6 (I think) 2011 model Diesel TDI automatic May, 11 - I picked up my car from a garage after an alternator change that failed. It runs fine after I get it back. I did some errands in town (I live 30 km outside of the city) but on the way home I get a Glow-Plug light blinking, followed by a lack of power and severe power loss during small uphill - found out what Limp mode is after that I send a message to the guys at the garage because one "car guy" told me maybe they forgot to plug something. I didnt get any text message back from them May 12 - The day after I decided to drive the car to a more sophisticated repair company that specializes in Skoda and VW. No warning lights for the first 4 minutes until the glow-plug light starts blinking again and limp mode. They hook it to a computer even thou they are busy but no slot available until June - After 10 minutes he asks if I have done some discreet or "illegal" fix to the car at any point. I say I know nothing about cars and wouldnt know how to - He asks: "Have you noticed the DPF light?" - I say "no". He says "follow me. I´ll show you" He shows me a new light I have never seen. The DPF light but he said he didn´t see any "glow-plug" when reading the car. He tells my it seems like there is an error with the Diesel Particle Filter system and the car is trying to send error regarding it but "someone" has prevent it to trigger the warning light itself - He also shows me the main error he gets in the reading and it´s P00299 - "Turbocharger/supercharger underboost" He advices me to drive the car a little "long haul" outside of the city to release soot inside the engine for an hour and possible it might fixes itself. But otherwise I have to make an appointment and they have to dig deeper into this. He denies this has anything to do with the changes on the alternator. I leave and as soon as I drive away the car starts to pollute a lot with huge smokes coming from the tail pipe the engulf the entire street. After a 4 minute driving the smoke stops, DPF lights goes away and "glow-plug" lights starts blinking again with limp mode. On my way home I visit my friend who is very well into cars and owns a car part shop. He opens the bonnet, checks hoses and other things and doesnt find anything unusual. He remove the tap from the oil and some light hot steam rises that he found not a good sign and told me he suspects this car doesn´t have much life left. He connects the car into a computer and spends an hour inside the car with engine running and a lot of emission coming from the tailpipe again. At the end he tells me he managed to bring the levels of the emission down to normal for the moment and also advices me to drive it and something outside of the city and check if its gonna be okay now. I did and at one point at a straight road with low traffic in a valley the car reaches 120 km/hr speed but it didnt happen quickly. I had to build the speed up over 2 minutes or so but "glow-plug" light was still on (I think) I turn around and go back and head home with 30 minutes to drive home but it goes back into Limp mode at every small uphill. At one place after a bigger uphill I couldn´t even get it beyond 30 km/hr speed and CHECK ENGINE lights appears for the first time and I barely made it home with hazards lights blinking. May 13 - The day after, I call the company with the Skoda specialists and told them about this and they said if the check engine light has come finally then probably I shouldnt drive it any more and next journey should be the one to the garage. He gave me appointment at 2, June but couldn´t say anything or have no high hopes. He said "it can be this and that" and worst case the turbine itself is gone and if so its probably not worth it to fix it Yesterday, May 16, for coincidence I met a guy through my work. A foreign guy who has lived here for 10 years. We spoke about this and that and turns out he is fixing cars. I tell him about my problem and he says in his home country Skoda has been the most popular car and like 90% of people there have at some point own a Skoda. He laughes and says "Skoda never dies". Its just a typical sensor problem that can come regularly. Its easy to fix and usually really cheap. So some say that my car is about to die, some say I just have to drive the problem away and this guy says its a cheap sensor fix Today, May 17, I haven´t touched the car now for 5 days because I am afraid of making some permanent damage to the engine