Check engine light on and engine vibrating when ignition turned off

[sapstar]

@Crasher Thank you very much for your help with fixing this problem.

I finally got some time to replace the inlet manifold today. I ordered a VDO one online, but they sent a Continental, guess it should be ok. I noticed there is little bit of oil in the turbo boost pipe and EGR valve. Is this expected? I wiped both before fitting the inlet manifold.
Once replaced, the judder when stopping the car is gone and also overall driving feels smoother. I cleared the code/check engine light, and it didn't come back on after a 15min drive on the highway.

One little issue I faced is when tightening the screws, I wasn't able to find the right torque wrench. I checked online that the screws should be tightened to 10nm. I only had a 28nm (min setting) torque wrench, so I turned them fairly tight without reaching 28nm, but not sure what torque I applied. Do I need to get a 10nm wrench and make sure they are all 10nm?

[Crasher]

Continental is VDO. I just nip them up, I have been doing it so long I have a torque wrench built into my wrist.