Error Code 43

I have been having some trouble with my 1997 Dakota. It has the 2.5l motor in it and I went through and checked pretty much everything that was recomended...put everything back together and I do get the check engine light. It indicated error code 43 which is:

43: Misfire detected in multiple cylinders. **

I have replaced the plugs, plug wires, cap, rotor, checked the injectors, fuel pressure, and air intake. Not sure what to do next.

Is it possible I routed the plug wires in such a way that it could be causing this problem? I read about a similar issue on a dodge web site, but there was no info on the proper way to have them routed. I thought I put them in the same way I took them out

If it is running the same way after the tune as it was before the tune up it could be a clogged catalytic converter, just had the same thing on a 98 camaro in the shop a week ago, see if you can disconnect the exhaust somewhere before the cat.