Diesel engine

I have a series 60 detroit engine in a international it has lost power the turbo seems fine i changed fuel filters and it has not helped. any ideas? and i have gotten codes out of it but i do not know were to go to find out what the mean. does anyone know were i can go to find out what the codes mean. ty

Here you can find some diesel engine talk forums:

http://www.dieselenginetrader.com/diesel_talk/index.cfm