Mazda 6 2.2 turbo underboost
 

Hi,
Looking for some advice on this please. For the first time yesterday the car (2014 2.2 skyactiv diesel, 41k on the clock) suddenly threw an “SCBS inspection required” warning message, along with a noticeable turbo lag up to around 2.8k revs. After stopping the car for around an hour, then driving again, the fault cleared (lag still present), but as soon as I reached any sort of speed, the fault returned, but this time with an “engine inspection required” message and the emissions light as well. When I got home I plugged my OBD reader in and I’m getting a P0299 Turbo Underboost code. Reading up it’s clear this is quite common and the cause can range from something simple to completely terminal - based on the symptoms what should I do next? Take it to Mazda and accept whatever monumental bill that could result in? Find an independent Mazda specialist (is there such a thing? In Worcestershire?)? Or a turbo specialist, assuming the fault lies with the turbo? This seems like something well outside the realms of your regular garage...

Thanks in advance.