No. The doser is at the entrance to the scr not DPF. That's what we call the 7th injector. 7th injector injects diesel fuel to heat up the DPF....
For the most part it depends on the mechanic doing the job. I am a mechanic and as an example a while ago I had an oil change and greasing Todo...
Exhaust brake = actual name for it Jake brake = name given to the exhaust brake by us mechanics because the person who invented it. Like calling...
That whistling sound is a leak. Somewhere. Like a ballon when you stretch the end and the more restricted it becomes it begins to whistle. Boost...
The clicking on startup is the abs system testing itself. I assume you mean the clicks when you put the key to the run position and not start....
That would be your output speed sensor. Unplug the sensor and on the pins( not the connector but pins on trans) test for resistance. Example...