Boost leak CM870......check engine light?

[tlzimmerman]

Well now I'm stumped. There was a rubber plug in the egr cooler. I removed it and was able to hook the egr tubing back up tight to it and clamp them down. Fired up the truck and took her for a spin with an empty trailer. Same noise....and I dont think it's building boost. I've got to work on all the other trucks today. I suppose the next step is taking the entire tubing off and check the integrity?