I have a 2004 IC bus with the dt466e engine.The last couple weeks he complained about the engine warning light coming on.He told me all the fluids were normal level.This morning I checked the bus for trouble codes.I got one a 120 said boost wasn't enough or erratic.I have 69000 miles on the bus with an allison.I couldn't find what the heck this means.Is there a place to find the codes on the net and where should I look and check to see if I can solve the problem. Thanks
Try typing the DTC # in to search engine such as Google or Bing (navistar 120 diagnostic trouble code) Or something like that. I have found plain english questions can be answered by searching the web, (What is the torque specification for head bolts on a DT-466) Wikipedia is a good source for info also. Even techincal.