I ran onto a guy who buys used cats from salvage yards and such. He showed me two huge items that I took to be semi mufflers. He said they were catalytic converters from “some big diesel truck”. I didn’t have the heart to tell him that I didn’t think that diesels have them. Am I wrong?

Do semi tractors have catalytic converters?

Whitey July 12, 2011, 1:23pm 5

Great answer, Tester.

nowmaybe, those catalytic converters your friend has may be from a new truck that was totalled in an accident. They could also be from an old gas burning truck, or from a large class A gasoline burning RV.