Hi All, new to this forum and my first post is to ask for advice from anyone that been here before. I see there's plenty of posts about this issue for disco's and jags but I haven't tracked down anything for a 405.

we have the def quality warning on the dash and the countdown. First assumption was to top up with new def but having searched that seems to have been the wrong thing to do. I also understand the warning isn't necessarily for fluid issues but also that the nox sensor is detecting the def isn't doing its job.

looks like a drain and clean the injector is the answer to start with so I'm asking if anyone can advise of location and method? Light googling suggests it's under a plate and has a drain hose.

any device appreciated.