I had an 05 wrangler with the I6 motor in it, and right after i bought it, I put a CAT back magnaflow exhaust on it. In the winter of 07, i was going to do a little wheelin in the powder, and i couldnt make it up the paved grades. Lost almost all power. For a week before that, i kept hearing my exhaust rattle when it was cold.

Come to find out, the CAT had failed, and fallen apart blocking my exhaust.

Jeep was 2 years old, with 35,000 miles on it.