I found a copy of the 1999 7.3l Powerstroke Diesel Powertrain Control/Emissions Diagnosis manual on Ebay for a triple-sawbuck and bought it. Man, that is one complete diagnosis manual and will be loaded into the truck along with my AE/laptop for any roadtrips. If you haven't seen this manual, you owe it to yourself. A hatip to Tugly for the recommendation.