Getting ready to change doser at the turbo

[Meanwhile]

I thank you all for taking time to help each other here! I've been reading posts off and on for the last year and have just registered today. I've learned a lot so far.

A year ago I bought a 2013 Kenworth T-660. It has a 485 CM2250 in it. While waiting for license plates I changed all the sensors suggested here and my list of things to check and change keeps growing.

I'm getting ready to change the doser out at the turbo. I bought new fuel and water lines also because they have rust scale on them. I also bought a new thermostat to change since I'm gonna have to drain the coolant.

My question to you all is, since the coolant will be drained, what else would you check? Another question is: Can the nox sensor be cleaned? Currently the motor has about 410,000 miles on it.

I'll continue to look around the topics more, forgive me if these questions have already been answered someplace else. Thank You!