Ford focus st3 diesel p2237 fault code.

So one morning driving home from work, mil popped on. Scanned the codes and p2237 was my only code at the time, so I started googling it and it said bank 1 sensor 1 oxygen sensor defected/died. 

I ordered a genuine sensor and what a nightmare getting it off!! 
changed the sensor and still code was still present, I then moved to change the plug on loom as apparently moisture gets into the plug and pins. took it auto electrician over the Xmas break but the code wasn’t on apparently even though I cleared it before leaving home and always comes on as it warms up and goes into closed loop, Code stayed off for 3 weeks then came back but then I got p2195 every time (running lean). All wiring was reading correctly to keep me guessing 🤬
 

my symptoms was poor mpg, constantly trying to do a regen, rough idle so I took it upon myself to carry on chasing this as graham Goode said they couldn’t get the code back up after clearing even though I told them how to get it to pop up again but didn’t listen and charged me £110 for the pleasure and wasn’t prepared to get ripped off any more. 

Went out last weekend with forscan and messed around the gearbox/egr area…..CODE OFF! Code came back yesterday going shopping so I decided to go back out and look again and found this area, and just as it runs up towards injectors off the plastic housing, felt quite squishy so I stripped it and replaced the loom tape but put more on it (more secure now). 
 

so far I’ve done 50 miles for work round trip and car has used 29 miles mostly motorway but before I was using 30 each way. Sorry for such a long post, just thought I’d explain what I’ve gone through and what I’ve done incase anyone else has this problem.
 

If the egr area doesn’t cure the code p2237 then the problem lies in the loom by the gearbox where it loops behind it the boost pipe towards pcm. Photo attached is the egr area that I did yesterday. I’ll update in few weeks as to how I’m getting on.