How to fix CMI Aft Fire mufflers
 

1. Remove the PoS air pump and throw it away. $350 each, 3 in 4 years
2. Remove the PoS air cylinders ( now $150 each) and throw away. They last a year or maybe two.
3. Remove the CMI butterfly valve and yep, throw it away.
4. Weld in GGB muffler inserts, comp model.

Now they work pretty well, the rings catch the water dumping and quiets it down.