CHIPPED OR NOT?

Car is 2016 Octy vRS diesel CUNA code engine, 150,000 miles. Does anyone know if there is an easy way to find out if the ECU has been chipped? Bought the car as the fourth owner and it came with 2cm wide wheel spacers all round which indicates that at least one of the past owners "pressed on" somewhat. In my ownership it's had the spacers removed (!!!), new DPF, new Bosch pressure & EGT sensors and repairs to a previously bodged turbo change; all done by a specialist VAG workshop I have been with for over 30 years with various Audi, Skoda and SEAT cars.

Since the DPF and EGT sensor change, it persistently throws error code P2084 usually after a bit of gentle acceleration, which the workshop says is nothing to worry about. There is no loss of performance and it clears with a basic code reader. The workshop believe it to have been chipped at some stage which is why it keeps throwing the code; is this feasible and is there any easy way to check?