You probably have a vacuum leak or a component failure in the "rat's nest" near the airbox that controls all the emission controls.
If you are getting a power surge around 1800-2000 rpms then your turbo is working.
If not, I suggest you do the pressure actuated wastegate mod.
You will have to buy the actuator and drill a hole somewhere in your intake but it's worth it and it eliminates multiple sources for vacuum leaks. It also eliminates the need for the EGR.
Here's the thread.
http://www.peachparts.com/shopforum/showthread.php?t=212097&highlight=OM602+wastegate+swap