I am surprised that a site like this should be so poorly endowed with knowledgeable contributors. I have learned the following from a number of resources:
The problem with the CP$ has been around since 2016. There are Class Action Law suits on going from Duramax and PSD owners as well as Cummins operators of Class A and Super C RVs and a number of commercial fleets.
The NHSA has been pressured to allow for a work around but since there are no spares available of replacement CP4 (faulty or not) and adapted CP3 HPFPs, nothing has been released. The incidence is quite low, affecting between 3 and 5% of the fleets. The cause of the failure is unknown but the speculation is that the diesel supply has changed since the CP$ was spec'd in 2015 and lack the lubricity that was assumed during the design. So one offset may be the enhanced use of lubricity additives but no one has proved to this yet and no one I have heard on is even attempting to do so.
Based on the problems faced by the Duramax and PSD owners, it is doubtful that Stellantis, RAM or Cummins will have replacements engineered, tested, manufactured or delivered in 2022. A manufacturer of gasket material for these and other pumps has been pressuring his customer folks to get commitments for the apparently "urgent" need to fulfill CP3+ orders, is getting no response, no indication even as to when capacity to make material for these replacement pumps.
So my perspective is to sell the truck to whoever, whenever; park it and lease something else, or see if you can find a dealer that will trade it on a new model. No one knows how, when or even whether this problem will be fixed given the supply chain issues and the impact the Ukraine war is having on European diesel components used by these pumps.
