go buy a bottle of windex.
Spray the entire air induction system down and look for boost leaks.
change the air dryer cartridge and if you haven't, the AHI module.
depending on the miles you have, you may even want to just replace the NOx sensors now too.
Get the SST gasket for the DEF injector, (Replace the DEF filter too). You can use a Fiber optic camera then to inspect the tube between the DPF and the SCR box to see if it's blocked with Crystalized DEF.
Then it will also depend on your tires. Get some Goodyear LHD or Michelin X-line Energy D tires.
post a picture of the tube between the Turbo and the CAC if you get a chance. I'm curious if you still have the compression clamps or have them been replaced since.
Take a picture too of the tailpipe. Be interesting to see the color of it., bare metal, black or white.