I have a small dent or more of a crease in my lower pipe that is keeping me from putting a baffle in. Its about 1.5 inches long. Is there any way to get that thing beat out? 2 1/8" ID

 

Some type of tail pipe expander or a mandrel may work.

 

Yea muffler shops have an expander. The secret is to tap the area around as you expand. This pushes our the dent.
That or find a pipe that just fits in and drive it in prying it out as you go.