670 with d13 lost power and mpg after repairs

2016 volvo 670 with d13 engine with 700k miles. Went to the dealer after getting stuck in derate. They replaced the 7th injector, cleaned the dpf filter, cleaned the fuel system due to algae, and replaced the injectors. Truck runs but I've lost power and mpg. Before repairs I was getting 7.2 with 45k load. Now 6.0 is the best with a 36k load at 60mph. Any small hill immediately drags it down as if I'm pulling a full load up a steep upgrade. Any ideas would be helpful. Thanks

 

After a week of running the check engine fault came on. I also believe the Def sensor is bad as it is always showing full so I have to fill it periodically to avoid any issues.