[Mik325tds]

Thanks for the appreciation points! That motivated me to continue this weekend even though my cojones where at risk of freezing to the garage floor...
Anyway, after removing the NOx sensor and post DPF temp sensor I found that I was working on the wrong end of things and misstated earlier in post #4 that these will have to be removed and installed in the downpipe from Jess. Obviously, that was wrong and has now been corrected. It is the pre-oxidative catalyst temp sensor and O2 sensor that need to be unscrewed see picture below: