EML - Piston cooling and NOx alert

[itom150]

Hi everyone,

driving down the motorway today my EML came on. Car is 2.0D 2017 125000 miles

booked in to Halfords next to work to at least diagnose as no other symptoms and they read the following codes:

p2BAE-00 NOx Exceedance
P25A9-13 piston Cooling Oil circuit/open
P049B-00 Exhaust Gas recirculation

like I say no other symptoms. Had a google of these and a few different things come up as expected. Not clear which one triggered the EML but seeing things from Ad-Blue sensor mucky or failing

piston solonoid failing or more onerous the timing chain is loose and cause this error. I know Inginium engines have timing chain issues so one to monitor but don’t have a low Oil warning or any issues with Oil level?

The garage reset the codes and they didn’t come back on but I’ve bought a carissa monitor so can at least monitor what comes back up more readily.
Also bought some wynns fuel and ad blue cleaning incase it is just mucky sensors. 

Any advice on what to check or keep an eye out for? Like I say 125000k miles so wondering if I should be looking at timing chain replacement regardless 🤔