I just bought a 87 Dodge Ram D150 that was beat up and just fixed up with superglue and duct tape by previous owners. I've started to fix it up(the right way) and now it runs and pretty much everything works but I've run into a problem.. today I had it idling and I was just checking everything out to make sure everything was good until I smelt almost like burning rubber?? So I turned the truck off and saw my mini catalytic converter smoking and honestly I can't find anything out it online or why it would do that. So please tell me why it would do that and how I can fix it.

 

It might be plugged up ,getting too hot and melting any undercoat above it.