Black smoke under load .

Hi guys I have a 2006 rrs 2 7 tdv6 129k jist towed my caravan to a local site. Just coming down motorway ans on inclines the car would drop down a gear being auto and nothing would happen apart from kicking black smoke out . Tried car with no caravan ans foot to floor there's a delay in turbo ans black smoke again. I've code read it while I'm here and here's what I've been greeted with on engine ecu .

P0402 exhaust gas recirculation excessive detected

P006aManifold absolutely pressure mass or airflow volume correlation

P0299 turbo/ supercharger underboost

Egr was blanked few years ago
Just serviced it few weeks ago .
It's allways has the off off of smoke out the back when flooring it as it does a lot of short journeys but never had issues
Cheers in advance for any guidance guts

Sounds like a split turbo hose ,,

One was correct . Staring straight at me ! New hose and 20 mins later I'm good to go ! Cheers guys !