The CP4 to CP3 Recall: Did the factory swap actually fix the reliability issues?

[Ryan]

My 2020 Ram finally got the CP3 pump swap under the Y78 recall. I’m happy to get rid of the "time bomb" CP4, but I’ve noticed a slight change in the engine sound at idle. For those who had the swap done, have you noticed any difference in fuel mileage or power delivery?

 

[TorqueTuned]

It’s a bit throatier at idle, but that’s the sound of reliability! The CP3 won't grenade on you. Peace of mind is worth the sound change.

 

[DieselStout]

2021+ models came with the CP3 from the factory. If you’re a 19-20 owner and haven’t done the recall, do it now before the CP4 takes out your injectors

 

[Ryan]

It’s a bit throatier at idle, but that’s the sound of reliability! The CP3 won't grenade on you. Peace of mind is worth the sound change.

Thanks for the reassurance, TorqueTuned! You're spot on—the peace of mind definitely outweighs that extra mechanical clatter at idle. I’d much rather hear the "sound of reliability" than worry about the CP4 sending metal glitter through my injectors.

Have you noticed if the CP3 handles cold starts any differently, or is it pretty much business as usual now that the "bomb" has been defused?

 

[BlackTopBound]

The sound change is totally normal. The CP3 is a three-piston pump, while the CP4 was a two-piston design. That different rhythmic 'tick' at idle is just the gear-driven CP3 doing its job. In terms of power, you won't lose anything—the CP3 has been the gold standard for Cummins for over a decade. You basically traded a fragile, high-pressure 'ticking bomb' for a legendary workhorse. I'd take a slightly louder idle over a $12k fuel system failure any day.