Ford Repair: 2006 lack of power, infrared thermometer, catalytic efficiency

Question
I am working on a 06 5.4 f350 that idles fine, but has no power.  Max rpm is only 3200 and when the throttle pedal is pressed past 1/4 it starts to stumble with no response past 1/4.  I've checked the fuel pressure inline at the filter, and its within spec.  Has pressure sensor, so cant test it at the rail.  Pulled the exhaust from the manifolds already, no major codes except a couple catalytic efficiency codes.  Cleared codes, none came back.  replaced fuel pressure sensor with known good one.  only have a code reader, no scanner.  I am an auto mechanic working in the bush, so I am kind of limited.  Just got me stumped without a scanner, was wondering if you had any ideas?  Thanks.  Lance.

Answer
The codes said it all. Catalyst below threshold may mean that the catalytic converters are stopped up. It certainly sounds like it. There is a really easy way to find out. Use an infrared thermometer to test before and after the catalytic converter. There should be a 100 degree difference.