When your 2020 Dodge Durango displays the P0303 code, the engine control module has identified consistent misfires in cylinder 3. The full-size SUV offers multiple engine options requiring different diagnostic approaches.
2020 Durango Engine Options
The 2020 Durango offers the 3.6L Pentastar V6 or 5.7L HEMI V8. On the V6, cylinder 3 is at the rear of the left (driver's side) bank. On the HEMI V8, cylinder 3 is on the driver's side. The 5.7L HEMI includes MDS cylinder deactivation.
Common Causes
- Ignition Coil Failure: Both engines use coil-on-plug ignition
- Spark Plug Wear: HEMI engines have specific plug requirements
- MDS Lifter Problems: 5.7L HEMI MDS system failures
- Fuel Injector Issues: Deposits or electrical failures
- Intake Manifold Leaks: Gasket or vacuum line failures
Diagnostic Approach
Identify your engine type first. Connect a diagnostic scanner to monitor misfire data. For 5.7L HEMI models, observe MDS operation and misfire correlation. Test ignition components systematically.
Repair Solutions
Replace faulty ignition coils with Mopar components. Follow proper HEMI spark plug procedures. For MDS-related failures, lifter replacement is typically necessary. Address fuel delivery and intake leak issues as diagnosed.