1997 Ford Explorer XLT

In reference to the 97 Explorer that is experiencing problems; I thought it was the four wheel drive. You asked me to go to a parking lot and do the following. 1.) In four wheel auto go in a tight circle. Result very little skipping, didn't feel great a little bogging or for a lack of a better word, slight dragging, not that bad campared to the following. 2.) In four wheel high same tight circle. Result plenty of skipping, dragging ( I call this bogging down), tire marks on the pavement. 3.) In four wheel low same tight circle. Results the same as four high, see results for 2 above. 4.) Four Wheel drive indicator light came on with little or no hesitation, both in four high and low, went off right away when I switced it to auto. 5.) Push vehicle on dry pavement. Results pushed with ease, considering the weight of vehicle, got a good push on it and it rolled to a slow stop after about 40 feet or so, on a fairly level lot. Drive home was bad; in 4 wheel auto, felt that bogging down feeling in lower speeds (city driving), about the whole way, 55 mph plus, bogging down was less of a factor, almost felt comfortable at times at higher speeds. Didn't have that get up and go from a stop. This morning I took it off my ramps, front end up, and it rode great for five miles or so. I did replace the motor drive to the transfer case. I also had the Transmission flushed out at one of those rip off places, figuring this will be a quick fix, I assumed they were going to take the pan off, but instead they did the top side flush. I put it on the ramps to take the pan off, drain it out all over again (thinking the screen may be clogged), but the little woman had different plans for me, work, not fun, rather be with my Explorer. On ramps for 2 days (haven’t done the tranny thing to it yet other then the top side flush as mentioned), don’t know if this had anything to do with the short good drive, front end elevated for 2 days, or just the fact it was sitting for over a week and cold. Anyway hope you can help thanks.

Took my Explorer into an Auto Parts place and had the codes read, Result no codes showed up (no bad codes). I appreciate any advise, thanks.

My Explorer has two Cats, expensive, dual coming out of engine then leading to a single muffler, looks like I got to waste the cats to dissconnect. No kinks or bends in pipe, cats look orginal, outside appearence looks good, dont know the inside shape till I disconnect. Shouldn't it of showed up in the codes? Is there another way to check air flow, since its dual cats (just to keep down cost), would pulling the spark plugs out be advisable, check for extra carbon uniformed on one side of cylinder head perhaps, if it is just one bad cat?