Ive have these codes (DTC P20EE00 / DTC P103C00) coming up now. Its the 2nd time Ive had one of these, the 1st time I needed a very fine crack wielded on the "SCR Catalysts" which is connected to a short flex pipe leading to the exhaust. Its very hard to see, but when its hot, working hard, that crack widens up causing a leak.. The Volvo Certified mechanic said that its a common problem, a flaw that Volvo does know about. I realize now, with these codes poping up again, and seeing the engine doing what it was doing similar to the last time, that its a waste of time trying to wield it. It really just needs to be replaced when it cracks...