My mother's 2005 Ford Escape 2.3L is having some issues.

First: I found out the valve cover was leaking, but only into the spark plug channels. I ordered another gasket and replaced it, leak fixed. And I cleaned up the channels.

Second: I was driving down the highway with two other people and a bunch of luggage going up hill and it topped out at about 68-70 mph, kicked to the lowest gear revved to around 5k rpms for a few seconds before it, without warning, threw a CEL, the engine started shaking violently, power was lost so dramatically that I had to pull over to the shoulder, and I appeared to burn through nearly an 8th of a tank of fuel in just that episode. I unplugged the battery, reset the ECU, and was able to continue on as if it never happened, BUT it still severely lacked power. The CEL was also gone and has yet to return.

Current symptoms:
When you accelerate, it moves forward a bit then bogs to nearly no acceleration, then picks back up slowly and continues up the band where it fails to properly shift into the next gear until 4500+ rpms. Before when it was normal, of course it didn't have much on the high end (Ford POS Crappola 4-Banger), but now it seems to have no high end at all. I haven't driven it over 35 or 40 since, but my mother claims it has diminished over the last two weeks (since the highway incident) and will hardly do over 40. I did, however, notice that when you get it up to say 35 mph and you are cruising with your foot stationary on the petal, the vehicle seems to "buck" slightly as if the fuel pressure was pulsing or there was some sort of transmission issue. I have noticed a very very faint whine - source unknown, and the engine doesn't produce any sounds that would make you think there was something wrong. I checked the oil and it was probably a 1/2 qt +/- beyond the maximum fill indicator. Transmission fluid seems normal. Engine temperature normal. A friend suggested the possibility of a clogged catalytic converter; can anyone confirm?

Thanks in advance for any help anyone is willing to offer.

Zach

For the current symptom check to see if the throttle position sensor is bad. I don't know about the whine you're talking about but a ford I used to own had very similar symptoms you described regarding the bogging.

I figured it out. The upstream catalytic converter was clogged up.