Well my good buddy finally cleaned out his garage and said I could use it to remove some broken bolts from the upper and lower intakes that Ive been putting off for several months now. I think I've got the bolt removal concept down but when I pulled the upper intake to gain access to them I noticed something odd about the intake ports. The front 5 seem to be nice and clean while the rear banks are soiled brown. What causes this? Is it something I should be worried about? The car has been running rougher latey but I thought it was because of the broken bolts (vacuum leaks). Any ideas? Thanks guys