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Low-cost automotive catalysts have been developed that contain 20-30% of the precious metals (7-15 g/ft3) commonly used in conventional catalysts, while providing a high efficiency of emissions control and durability for vehicles operating in emerging market countries. These catalysts were reformulated by replacing the Pd, Pt and Rh mixtures with optimized mixtures of rare-earth oxides (REOs). Laboratory studies demonstrated that these aged REO catalysts (80,000 km) with unleaded Chinese fuels reduce vehicle emissions by an average of 99%, 80% and 92% for CO, HC and NOx, respectively, when operating as a three-way catalyst in a closed-loop control mode at a stoichiometric air-to-fuel ratio. REO catalysts with 7.6g/ft3 of precious metals were tested on in-use Chinese Volkswagen Santanas with carbureted engine. Several strategies for air injection were tested on these vehicles.

Rotary position sensors (RPS) currently are applied widely in engine management systems for throttle position sensing and are being considered for other applications such as drive-by-wire. The potentiometer RPS relies on contact between a resistive element and a wiper and thus has an inherent wear mechanism. This paper describes a noncontacting RPS which is essentially a drop-in replacement for the present device. A linear output Hall Effect IC is key to achieving the required functionality, but it must be combined with a magnetic actuation scheme which provides a very linear and stable magnetic field as a function of input angle and packaging which provides long life and control of mechanical tolerances. Each of these design elements will be discussed.