EPC Light! A3 1.8tfsi

Hi guys,

I purchased an Audi a3 last week with 12,000 miles. Just hoping its not a lemon..

It's the 8V shape, 1.8 tfsi, 2013 plate. MQB platform. Manual.

I'm having the issue of the EPC light coming on when throttling the accelerator above certain speed.
Last week i took it into my local garage- they plugged it into the computer and found the fault as turbo related. The dump valve i believe, this plastic part on it had broken- apparently it is common as they are quite weak. This was replaced and a new one put in to solve the issue.

However i'm still having the same issue!

For the EPC light to come on- i will need to be in third gear revving circa 4-5k for the light to come on. As the light comes on the car has a slight hiccup but carries on driving- making no additional noise or anything. The car can continue to drive at 70mph in 6th gear with no worries, and can still accelerate to higher speeds. If i restart the car, the light will disappear, but if i mimic the above the light will come on again.
Further to this, the exhaust in general is quite smokey- whitish i'd say. The coolant level has never dropped nor has the engine oil light came on. It has also had a recent audi service for oil.

When the EPC light is on, the stop start also stops working.

Would you guys perhaps know why the EPC keeps being triggered?

Thanks!

Yes i bought it privately, not from audi.

I was always sceptical about the mileage but i have history showing that the mileage is genuine. The car i part ex'd had 30k on the clock and was 11 years old

I've already registered to myaudi and can see the service history, i have also previously contacted the call centre and they provided me with documents showing that when the car came in and etc. They did advise me that the warranty has expired on it.. :/