Five Hundred AWD V6-3.0L VIN 1 (2005)
Underbody Catalyst
The underbody catalyst is located afier the light off catalyst. The underbody catalyst may be in-line with the light off catalyst or the underbody catalyst
may be common to 2 light off catalysts forming a Y pipe configuration.
Three-Way Catalytic Converter
The 3-way catalytic (TWC) converter contains either platinum (Pt) and rhodium (Rh) or palladium (Pd) and rhodium (Rh). The TWC converter
catalyzes the oxidation reactions of unburned HCs and CO and the reduction reaction of NO. The 3-way conversion can be best accomplished by
always operating the engine air fuel/ratio at or close to stoichiometry.
Exhaust Manifold Runners
The exhaust manifold runners collect exhaust gases from engine cylinders. The number of exhaust manifolds and exhaust manifold runners depends on
the engine configuration and number of cylinders.
Exhaust Pipes
Exhaust pipes are usually treated during manufacturing with an anti-corrosive coating agent to increase the life of the product. The pipes serve as
guides for the flow of exhaust gases from the engine exhaust manifold through the catalytic converter and the muffler.
Heated Oxygen Sensors (HO2S)
The HO2S provide the powertrain control module (PCM) with voltage and frequency information related to the oxygen content of the exhaust gas. For
information on the HO2S refer to PCM Inputs in this section.
Muffler
Mufflers are usually treated during manufacturing with an anti-corrosive coating agent to increase the life of the product. The muffler reduces the level
of noise produced by the engine and also reduces the noise produced by exhaust gases as they travel from the catalytic converter to the atmosphere.
