have them recheck the t-belt+ balancer belt alignment...it sounds to me as if they are misaligned...........also make sure to ask them if they installed a 10mm bolt on the tensioner to hold it down ,,,,,,if they did it should not be there

I hope that some other member can show you a picture of what i am talking about ,,,,As a matter of facts there is a write up on the DIY section that has pictures ,take a look there

 

Well, thank you all for the replies. I, however, did take the car to the mountains and fortunately, it worked fine. Nonetheless, the low power is still felt in gear 1 to 3. I usually shift from 1st to 2nd or 2nd to 3rd at 2000 to 2500 RPM (I hope that is how everyone shifts), and during this shifting, I do not seem to get much acceleration, but car does not buck at any point. Something vibrates or resonates exactly at 1500 RPM somewhere in the car erratically. The problem of car being noisy while in gears 1, 2 or 3 still exists and it puzzles me since the RPM usually does not exceed beyond 3500. I wonder if it is connected to low acceleration as well.
Could this noise and low acceleration be an indicative of failing catalytic converter?
Are these things connected and related to the timing belt job?

Can the issue of acceleration be taken care of by replacing the spark plugs and wires? I do not think they have been replaced in the past 3 years.

Thanks for any suggestions and opinions.

 

If the timing belt & balancer belt were not lined up properly, it can cause this. That's why you need to go back & have them check it out soon, to establish that it was from the way they re-assembled things.

Then, new spark plugs might be a good idea, depending on miles. And you can check your plug wires for arcing (dull blue glow when you start it up in complete darkness).