EPA publishes a considerable amount of vehicle data for each model year at the following URL:
http://www.epa.gov/otaq/crttst.htm
Included in the downloadable data files are target A, B and C coefficients generated by the auto companies from coast-down data that are used for setting up chassis...
Pd is replacing Pt quite a bit in newer catalyst designs. It is cheaper and generally can withstand higher temperatures. Manifold-mounted light-off catalysts are generally Pd-only. Destructive testing is probably the only way to know for sure, but under-floor 3-way catalysts with ~0:16:1...