For years I have had intermittent power issues on my OBD1 3.0. Idles ok but sometimes when I am at partial throttle I can feel the engine dragging, so I floor it and it revs but acceleration is half of what it should be. then next thing you know it feels fine. I will gain and loose power multiple times through a single drive without turning it off and on. About 25,000 miles ago the head was pulled and re-done due to a burned exhaust valve but it didn't cure the intermittent power loss issue. O2 sensor and fuel filter replaced not long ago using OEM parts, they didn't help. I am now guessing the cat may be clogged, would that make sense? I never replaced the catalytic converter and I've had the truck since 80,000 miles, now have 253,000. I am set to do a 3.4 swap shortly so I don't want to put any more money into the 3.0. I also don't want to needlessly buy an expensive new cat. I was thinking about putting in a test pipe for a while and see what happens. Thoughts or ideas? Thanks in advance.