Engine low power up a hill

Sounds like a catalytic converter, to me, too. Disconnect it and take it for a test drive. Preferably install a test pipe where te converter should go to keep back pressure where it should be and sound levels down.

Just to add to this one you replaced the coil pack what about the ignition module?Also did you replace the spark plugs?Your best bet is to take it to a exhaust shop and have them do whats called a back pressure test. If its not the cat it could be that the timing chain jumped.I have seen a lot of them jump on those and if they jump enough it will cause a missfire and the cooling fan to stay on while it runs. Let me know what you find I have also replaced a ton of cats on those cars also. Does the ever not shift to the next gear up untill you ket off the gas a little?If so its most likely a plugged cat.

I dont think the mud did it but if it wont shift till you let off the gas the first thing I would do is take it to a exhaust shop and have them do a back pressure test. Let me know what you find.