ords

Sounds like the glow plugs are not working properly, hence the smoke. How are you checking for codes?

Can you take an image of all the writing on the label?

How does it sound whilst warming up?

You could try this first

Get it checked for code errors. Garage receipts should detail what was done and replaced How does the car run when the light is on?

What make is it? Mines a Varta AGM from Jan 2013

Mine was done on a recall, probably around 2014/15

I also do that. You can either just delete everything on the card or re-format it. The CID file mentioned by @langers2k will not be deleted which either method you use.

Support for MIB1 map updates has been discontinued. The latest and final update is "ECE 2020/21"

If he fixed the sump for what you must have thought a fair price and its been problem free, why don't you trust him? Could be many reasons why he couldn't show you the old parts. Did you say beforehand you want to see the old parts? Did he say how he would fix the sump? As you're not experiencing any problems with the gearbox or getting any fault codes, I'd go with the £120 repair.

I believe the gearbox takes 1.7L of oil, the mechatronics unit takes 1L The mechatronic oil seems to come in 1L packs.

You said in your other post you heard a clicking noise in reverse.

Maybe you can contact this OP for info

Probably something like this https://kinergo.eu/product/dsg-7-03-dsg-7-dq200-repair-kit/

Where did you get the idea that there was a seperate controller, when @ApertureS suggests they maybe controlled by the bcm?

Good that it was a simple fix. Surprised no error codes showed up.

How full was the tank before refuelling?

If it's bad fuel, how can changing the filter make a difference? It will be the same "bad" fuel going thru the new filter. Had you just refuelled? Get it scanned for error codes.

Go to the local store and try before you buy.

When I used to use ECO, mine never came out of coasting mode going downhill and I had to shift to lower gears manually to take advantage of enging braking.

There must be fault codes logged for the supposed corruption? If the ECU is corrupted how is the engine even running?

Agree. Mine only has basic cc but the 1mph increments are very useful. Maybe yours could be adjusted with vcd's coding.

What happens after the car slows down?

You need to find out why s/s is working when it's doing a regen. That's not right.