Exhaust System: Description and Operation

The exhaust system will vary between engine, transmission and vehicle models:
- The 5.4L, 6.8L and the 7.3L engine use a single Three Way Catalytic Converter (TWC).
- The 4.2L and the 4.6L engines use dual three way catalytic converters.
- The 4.2L and the 4.6L engines have two Heated Oxygen Sensors (HO2S) mounted after the three way catalytic converter.
- The 4.2L engine heated oxygen sensors are mounted in the exhaust manifolds.
- The 4.6L engine heated oxygen sensors are mounted in the three way catalytic converter.