Yes, these are things to consider:

cracked manifold-- unfortunately common except on EX which has a different type of manifold. If you have a real EX (and not something that has been swapped back to LX parts) there will be a cast iron manifold and a separate catalytic converter underneath the car. Check for exhaust leaks (from the manifold or anywhere else) by idling the engine while you have someone block the tailpipe with a rag. A crack will make a hissing noise from the pressure.

wrong timing-- always set timing with a light after replacing timing belt.

...valve clearance. You can often spot this simply by taking the valve cover off with the engine warm and make sure that the rocker arms all go slack on the valves that are supposed to be closed. You will need to turn the engine by hand (socket wrench on the crank bolt) to close some of the valves. If it seems there is a problem, get a feeler gauge and adjust the clearance-- with the engine cold. (Remove socket wrench before attempting to start!)

 

Well I didn't have time to tinker with the car today, and I won't have time to get to it until Sunday. My goal for Sunday is to crack the valve cover and check and adjust the spacing on the valves. I'll also test for an exhaust leak using that towel method that the guy that posted above suggested. Is there any other maintenance that you guys can think of that I can do or check while I have the valve cover off? Thanks for the help guys. Hopefully I can nip this pesky code in the butt come Sunday.