This vehicle came in with the driver complaining of intermittent smoking. I road tested it and did approx 30 miles then had to stop at lights. Whilst idling it began to billow out greyish white smoke then as I pulled away it disappeared. Exactly the same thing happened after another 8 miles. Codes stored are P1811 eng torque signal malfunction, P0380 glow device circuit general error and P0070 ambient air temp sensor.We fitted a non genuine DPF about 7 months ago because of lack of power, but there is certainly no lack of power now. Any clues or suggestions would be very welcome,cheers dave.