Loss of power/ car sounds like a suby

Hey, I finished with the timing belt job but, something is deffinatly messed up. I am 99.9% every timing mark was just how it should be. I checked them so many times before installing the belt. I made sure the oil pump pully rotated counter-clockwise (towards the timing mark) and everything. However, now my car sounds like a suby. It has very low power in the low rpms but once it gets in the higher rpms it sounds just how it did before and it pulls just like before. The car also has virbrations in the lower rpms but the vibration goes away in the higher rpms. The car sounds like its chugging along. I popped 3 cels too. One was a fuel trim malf.(which I had before the job) and another was cylinder 4 misfire. The other one I couldn't figure out. Any help would be great.

A friend of mine suggested that the number 4 injector could be clogged. This is a possibility seeing that the fuel rail was off but, I am not sure that this is the problem seeing that at high rpms it runs fine. I'll get the fuel rail off and crank the motor over to see if they all spray gas and I'll post the results. Oh and btw I also checked compression and they were all very close to 145.

Yay, it's fixed. I pulled the fuel rail off with the injectors and the number 4 injector had a piece of the lower seal torn and jammed into the injector. I pulled it out put it back together and she runs like a beast now.