Is the CP4 pump really that bad?
Is the CP4 pump really that bad? Why Is the CP4 Pump Allegedly Failing? The primary reason the CP4 pump is said to fail is because the pump was not designed for diesel fuel in the United States. Bosch is a European company, and Europe uses diesel fuel with more sulfur than U.S. diesel fuel. Do you need to replace fuel pump on 2005 Dodge Ram? Fuel pumps with the freeze plugs blown out will need to be replaced, and the core is not eligible for exchange. If you’re having troubles with 2005 Dodge Ram with 5.9L Cummins Diesel pumps,...