I just had my 2014 Fleetwood Excursion into a Freightliner Oasis dealer earlier this year.  They found a Cummins emission systems recall and performed the update.

The problem is, the RV was into my local Freightliner (not Oasis) shop four times over three years and there was no mention of the recall.  My local shop is also Cummins certified.  Even worse, the person I purchased the RV from also used a Freightliner shop, (not the same as mine) and they never mentioned the recall.

When I approached Freightliner at the Hershey RV Show, they denied that it was there problem to handle the recall!  I spoke to Cummins and their reaction as pretty much that the person I spoke with at Freightliner was blowing smoke.

Once the serial number of the engine is put into Freightliner's system, the recall should pop up.  The systems are supposed to be interconnected.

https://www.cnet.com/roadshow/news/epa-cummins-emissions-control-systems-recall/

If you have an older 6.7L Cummins engine, you might want to investigate the recall.