The local muffler shop says that I need a new converter? What are the symptoms of a bad converter? The truck seems to be running fine.

 

High emissions! You will eventually develop a raw egg smell from the exhaust, as well as a lower peak rpm. In fact, high rpms will become more and more limited. Highway driving will suffer worse gas mileage, and what will feel like a loss of power. Eventually, the truck will bog when you try to accelerate.

Take care,
-Chris

 

No power. If you floor it and it does practically nothing then your cat is plugged. Once you do that look under your car and most likley the cat will be cherry red.