The SCV is the usual culprit for those exact symptoms, but since you've changed yours it may be some varnish or similar in the fuel system. A good injector clean may be all it needs (and can't hurt). 2 choices:
1) Add a bottle of Liqui Moly Fuel System Treatment to your fuel tank and drive the car. It might take 200km before you notice an improvement, depends on how bad it is.
2) Use a bottle of Liqui Moly Diesel Purge. There are YouTube vids on doing this, instructions also on the can. No need to drive this one, just use the can up and you're done.
I'd also check the air filter, and use some electrical contact cleaner on the MAFS.
Is it making any weird squealing noises?
Look over the exhaust system (including EGR). Any black sooty deposits showing anywhere?
Has the EGR been blocked? Sometimes the EGR valves can develop a fault and introduce too much EGR, which will choke the engine. Your 2010 model won't have a problem if you block the EGR. Remove the 2 12mm bolts holding the EGR tube to the EGR valve body. Remove the gasket, make a copy out of 1mm stainless steel sheet but conveniently forget to do the big hole. Reassemble (preferably with a little sensor-safe gasket cement).
