IIRC you can test for a clogged cat with a vacuum gauge. Hook it to a source of manifold vacuum and rev the engine to 4K rpms or so and if the vacuum drops off (after initial stabilization at 4K rpms) then you've got a restriction in the exhaust system.

Karl


*** It's all about consistency! ***

98 SVT Contour
86 Ranger GT
69 Fiat 850 Sport Spider
67 Formula-S Barracuda