So I got this car used just recently and it has almost 110,000 miles on it. Figured out that it is time for timing belt change. During the process, I noticed that one vacuum line (noted by the red line in first picture, it is on right side of the engine) might be connected by some sort of heat shrink tube and it really shrinked, shown in the second picture.



Could anybody identify that line?

 

when you find out what it is, post it here. I too would like to know what it is.