I had asked about this some time ago - exhaust brake time to be exact.
Seems I remember someone said that around 2001 they started putting them on injection pump and ECM - but not all trucks got them and there was no way to tell which ones did and which ones didn't. That's my recollection anyway.
FYI - the Cummins/Dodge/Jacobs exhaust brake tells you to remove the connector from the ECM (no mention of void stickers. ) The Cummins and Dodge techs I talked to on the phone said there would be no issues with removing it. However, that doesn't say that adding performance enhancements won't be an issue. If you're prepared to play, you should be prepared to pay (for items that could be affected. )