Catalytic converters eliminate many harmful exhaust contents that are expelled from the engine before the exhaust is released through the muffler. On a Ford 6.0 diesel truck, the catalytic converter is between the exhaust manifold and the muffler. Over time, it can get worn out, and eventually you'll need to replace it. Removing a catalytic converter is a relatively simple process.
Slide under the driver-side door of your truck.
Locate the catalytic converter, which is a tube approximately 1 foot long bolted into the exhaust system. It's bolted with four bolts to the exhaust pipe leaving the rear of the engine and another four bolts to the exhaust pipe leading to the muffler.
Unscrew the bolts using a properly sized wrench.
Pull the catalytic converter from between the exhaust pipes. It will most likely be rusted into place, so you might have to pull firmly.
