Conversion Efficiency of a 2-Way Catalyst Fitted in a Used Vehicle without Feedback Emission Control System

Emission control in the city of Cairo has been a major concern in the recent years. The big issue is that most of the vehicles in Egypt aren't equipped with any emission control device. Fitting a catalytic converter in a used vehicle without a proper emission control system is a big question. In this paper, the performance of a two-way catalytic converter fitted in a used gasoline-fueled vehicle is examined. The air to fuel ratio of the mixture supplied to the engine is conventionally controlled without any closed-loop control system. The converter is a platinum/palladium (Pt/Pd) catalyst with 400 cells per square inch. The engine is mapped at a designed test matrix to include various operating conditions. The catalyst conversion efficiency for CO and HC emission was higher than 98 and 90 % respectively at most of the load ranges. For the very low loads including idle condition and at maximum power condition, the conversion efficiency dropped to 60 and 30 % for CO and HC respectively. The conversion efficiency of CO was higher than that of HC and it was less sensitive to the changes in the air fuel ratio. It took almost 8 minutes for the catalyst to respond for a cold starting engine.