What is this and what does it do?!?!?!

[feusaf]

So...there I was...driving down the road, truck started to cough and idle really rough so I went straight home and popped the hood. I found the little gray line laying on the right side of the motor and I assume it plugs into the little actuator in the picture...but what does it do, and most of all, would it make my truck run like crap????

To make a long story short, I bought this fine 6.0 back in March and on the drive home from the dealer, the VGT solenoid went out...got that replaced under warranty and two months later, had to take it into the dealer because it was running rought, surging, coughing, you name it, it did it. They repalced the EGR Valve and sent me on my way. One month after that, it started all over again and they replaced the heads, EGR valve, EGR cooler, Oil Cooler and a few other things.

Here I am 5,000 miles later and having more problems. Could it be as simple as this little vacuum line?

[Clay Henry]

That line goes on that black valve...it operates the heater - shuts off hot water to the heater core when the temp. knob it set to cold.

[feusaf]

Thanks for the quick reply to my post! But, if that vacuum line wasn't connected, would it cause the engine to run like crap?