Dodge Stratus performance problem

Hi,

I have a 2002 Dodge stratus SXT, 2.4l I4 DOHC engine with 90000 miles on it. Recently I got the following service performed on the car:

1) 90k service - including oil/air filter change, spark plugs replaced etc.
2) Timing belt replaced
3) Tensioner and water pump replaced
4) Transmission fluid replaced.

note - Technician had disconnected the PCM from the battery.

Now after I got the car back there is a strange problem. The car runs fine in the lower RPMs. But as soon as the RPM goes above 2500, the engine sounds as if an extra load had been added to it and it feels noticeable sluggish. The engine sounds rough. This problem is especially noticeable when I am tackling the mountain roads at freeway speeds. The car needs to be in the higher RMPs but as soon as the RPM level goes up, the engine goes sluggish and car doesn't speed up. I have travelled on the same raod several times and the car used to tackle it with ease.
I know the technician screwed up something but dont know what. It doesnt feel like a tranmission slippage. I took the car at the service center and they tested it on the road and with the scanner but found no codes/problem.
One thing the technician did tell me was that since he had disconnected the PCM, it got reset and needs to relearn all the settings again - i.E. The shift points for the transmission. But its been 2 weeks I have driven the car and I suppose its enough time to relearn the new settings.
Can some one tell me what could be the problem?

Thanks in advance,
Amol Purohit