Exhaust system soot?

[gedgell]

I recently changed the exhaust system - cat back to a new Bosal unit. Old muffler had a few holes. I noticed the interior of the old exhaust pipe has a complete coating of black soot. My truck is an 89 22RE 5 speed with 90K original miles on it. I have had it 5 years and have only put about 6K on it with mostly real short trips. Is that he cause of the soot? I get pretty good gas mileage when I drive more than short trips.

The truck is pretty slow to warm up - going by the temp gauge and never runs mor than a third of the way to the red. It has absolutelu no drivability problems. Is the soot normal.

[89Truk]

Perfectly normal, the burning of fuel produces carbon. Your new cat back will get black eventually.