1999 Chevy Tahoe Too much Condensation

I keep this truck in the garage and only drive it on the weekends. Lately when I start it up, it lets out a lot of condensation from the single exhaust. I drive it approx. 10 to 15 mile and the condensation is still coming out of my exhaust. Eventually the condensation goes away. My oil is good and clean, the water level is good. Although I have a leak in my muffler. The condensation comes out of my exhaust a little longer that normal to me. I'm a little worry about it. Can someone please help me with this issue?