Yellow engine light and low power

[akula80]

Just looking your guys advice on my w204 2012 sport plus. Yesterday I thought it was driving differently more specific changing gear differently. It seemed to be hanging onto the gear for longer. Today still doing the same but the yellow engine management light came on. So it put it into sport mode and there was a lack of power.
I do mostly short 12 mile journeys everyday and very very few long trips. I know this could be a lot of things but if it needed a dpf regen would it give these symptoms. Just hoping something simple. It did just get a fill of supermarket fuel which it never gets a few days ago.

Any advice greatly received

 

[chubbs111]

it needs to be put on a star machine instead of guessing and throwing money at it