Catalytic Converters
The catalytic converter(s) is installed in the exhaust system in front of the muffler so that all exhaust gases must pass through it. The converter is a stainless steel, muffler shaped, device that reduces exhaust emissions.
There are 2 types of catalytic converters, oxidation and 3-way converters. The oxidation type converter contains material that is coated with platinum and palladium. This catalyst reduces hydrocarbons (HC) and carbon monoxide (CO).
The 3-way converters contain material coated with platinum, palladium and rhodium. This catalyst reduces hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NOx).
The catalyst may be one of 2 types: a honeycomb-type block that is non-serviceable, or small ceramic beads that can be removed and replaced on some models.
Use only unleaded fuel on vehicles equipped with a catalytic converter. If leaded fuel is used, the Tetra Ethyl Lead in the fuel will coat the palladium, platinum and rhodium. If this coating effect takes place, the converter is useless. If this happens, the converter must be replaced.
The 3-way catalytic converter is used in conjunction with the conventional oxidation catalytic converter. All models with the oxygen sensor/feedback carburetor system use this type of converter.
Ford Motor Co. uses 2 separate converters. On some Ford Motor Co. models, the first converter in the exhaust system is a light off catalyst converter. This is a single bed converter designed to control exhaust emissions during engine warm-up, when the main converter is not at a temperature required for maximum efficiency.
On all other models, the first converter (3-way) in the exhaust system reduces hydrocarbons (HC) and carbon monoxide (CO), but mainly oxides of nitrogen (NOx). The second converter (oxidation type) reduces, with extra air from the air pump, hydrocarbons (HC) and carbon monoxide (CO) only.