My 2012 Octavia II 2.0Tdi CR 150 is producing white smoke from the exhaust and running at a fast idle, around 1000rpm, as if trying to continually attempt a passive regeneration of the DPF and think this may be causing it to over fuel pumping excess diesel into the DPF and hence the white smoke. Anybody who has seen my previous posts know I have had a long term issue with the DPF etc. However, after having the EGR replaced, the DPF cleaned recently and the turbo replaced a while ago this is still happening. I found an earlier post (which I can now not find!) regarding undertaking a run gathering live data through VCDS? I know when the turbo was replaced the garage had a problem with the oxygen sensor which they replaced at the time. I also had a replacement throttle body fitted bit it is not a genuine part. I have an official VCDS set up and was wondering what data I would be looking to get to check out the relevant sensors etc? When I have run checks on it before I have had doubts about both the coolant temperature, gauge indicates 90 degrees while VCDS logs 75 degrees. Similarly I think the Exhaust temperature readings are lower than expected but this is just a snap shot reading not live data. I have taken the car on long fast road runs to ensure it gets as hot as possible. Everything else, oil, water and power check out ok. 

1 hour ago, ronnievincent said:

2.0Tdi CR 150 is producing white smoke from the exhaust

Well, if that's any time other than during start/warm up I'd suspect head gasket failure.

3 hours ago, KenONeill said:

Well, if that's any time other than during start/warm up I'd suspect head gasket failure.

Hi, thanks for the input but definitely not the head gasket. It's been doing it for sometime and have been working through the components with a replacement EGR valve last week. No other signs such as oil / water mix, no increase in oil level or overheating.