Over the past few days while I've been tracing all my vacuum lines, I've noticed that the previous owner replaced a lot of the rubber lines with these SMALL hard plastic lines. They are small enough to fit inside the stock lines. I was trying to figure out the reasoning for using these and the only think I could think of was maybe for the heat?? But being that these lines are smaller than the others, could that cause any issues with the car? What do you guys think?