99 Honda Replaced Catalytic Converter & VTEC Solinod

I recently had my check engine light come on and the RPMs were all over the place. I took it in and they told me I needed a new catalytic converter and VTEC Solinod. They did the work and now two weeks later it is doing the same thing which is when I hit the gas the car has a hard time speeding up and when I take my foot off the gas the RPMs shoot up for a second, the shifting is hard too. The check engine light has not come back on though. Before I take it back, does anyone have any idea what might be going on? There is no noise, it sounds fine...its just very sluggish when speeding up.