The TT uses a completely different style of gearbox, but due to the power output it would have to have a wet clutch. The dry clutch is not suitable for more powerful engines as it can't transmit the power reliably for long periods.The fix is the software downgrade to remove the method the manufacturer used to allow the car to detect it was undergoing an emission test. The test used a rolling road, with variable speeds to a set pattern and no steering movement. When it knew it was being tested it used its emission equipment much more aggressively, but did not really use it so in real use. Following the fix it uses the equipment aggressively all the time, often leading to rapid failure of the EGR valve and DPF exhaust, both of which are expensive to replace, and could well fail again after a short period. (EGR = Exhaust Gas Recirculation to send exhaust gasses back to the inlet of the engine and burn it again, often clogging the valve with a sooty oily residue. DPF is the Diesel Particulate Filter, which traps the small particles, burns them off regularly, but once the ash trap is full has to be changed)
If you do a search on the site, there are loads of posts on this and how to find out if your car has had it done. Any car sent to the dealer for servicing will have had it done, unless the owner specifically said no; it will be called a software update with an innocuous name. Any car sold via a Skoda dealer will be done.
It may be possible to go to a specialist and have the car re-mapped to remove this, I am not convinced it totally resets the cat though?
A Euro 6 car, with the adblu tank under the boot floor is not affected by this, using adblu to solve the emissions problem, with much less use of the EGR and DPF. These came out in 2015 but could only be bought in 110ps and 150ps versions, with the 170ps no longer available.
Personally I find the performance from my 150ps entirely adequate; the most powerful car I have ever leased/owned in over 40 years driving
Edited by: ken3966