Need help, series 60

Where is the vpod located how do you replace it?

 

It is inside ECM, Li battery. Easy to damage ECM desoldering old one, so look for profi

 

I had same problem it was the exhaust gas pressure sensor they replaced it and good as new they say the sensor was confusing the other parts make them less performance and making funny sounds

 

Gasping for air?

There is a intercooler to turbo feed with clamps, a large pipe. Check and see if those clamps are tight and there are no holes in same or blockage anywhere in the air intake side.

The rest of it, I'll leave to others. To me I think your shop is not interested in fixing the truck. Find another one.