The 2022 Ram 1500 delivers exceptional capability with either the powerful 5.7L HEMI V8 or efficient 3.6L Pentastar V6 engine. When your Ram 1500 displays a P0304 code indicating a cylinder 4 misfire, systematic diagnosis identifies the cause whether it's ignition, fuel, or mechanical in nature.
Understanding P0304 in Your Ram 1500
Cylinder 4 location depends on your engine. In the HEMI V8, cylinder 4 is on the right (passenger) bank. In the Pentastar V6, cylinder 4 is also on the right bank toward the rear. Both engines use individual coil-on-plug ignition allowing precise misfire detection and targeted diagnosis.
HEMI MDS System Issues
The HEMI's Multi-Displacement System is a common source of misfire concerns. Cylinder 4 is one of the cylinders that deactivates under light load. Worn or stuck MDS lifters can cause misfires, particularly noticeable when the system activates during highway cruising. The MDS solenoids controlling oil flow to the lifters can also fail.
Diagnostic Process
Access the cylinder 4 ignition coil on the right bank. Remove the spark plug and inspect electrode condition. On HEMI models, pay attention to when misfires occur—during steady-state cruising suggests MDS involvement. Check for intake manifold vacuum leaks and verify fuel injector operation.
Repair Recommendations
Replace spark plugs with Mopar specifications. Test ignition coil output. If MDS lifter issues are suspected on the HEMI, a lifter replacement may be necessary. Some owners opt for MDS delete kits to eliminate this system entirely, though this affects fuel economy.