2010 Dodge Charger SXT Check Engine Light & Rough Idle Troubleshooting
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A rough idle with a lit MIL on the 2010 Charger SXT often points to ignition, air-fuel, or EVAP issues. This guide explains how to diagnose and fix the problem using a structured approach—all in English.
- Applies to: 2010 Charger SXT equipped with the 3.5L V6.
- Tools: Enhanced OBD-II scanner (Mode $06$), smoke machine, fuel pressure gauge, DVOM, throttle body cleaner.
- Immediate reminder: A flashing MIL indicates severe misfire; reduce load immediately to protect catalysts.
Likely Codes and Causes
| Code | Subsystem | Likely Cause | First Checks |
|---|---|---|---|
| P0300/P030x | Ignition/Fuel | Coils, spark plugs, injector imbalance, carbon buildup | Inspect plugs, swap coils, clean throttle body, perform compression test. |
| P0171/P0174 | Fuel Trim | Lean mixture from intake leaks or weak fuel pump | Smoke-test intake, inspect PCV hose, measure fuel pressure under load. |
| P050D | Cold Start Rough Idle | Carboned injectors, intake leaks, coolant sensor bias | Use injector cleaner, check intake gaskets, verify coolant temperature sensor readings. |
| P0456/P0457 | EVAP | Small leak or loose cap causing rough idle | Inspect fuel cap, command purge closed, apply smoke to EVAP system. |
| P2101/P2110 | ETC/Throttle | Throttle body contamination or ETC motor faults | Clean throttle body, perform ETC relearn, inspect throttle wiring. |
Diagnostic Workflow
- Capture baseline data: Save DTCs, freeze-frame, Mode $06$ misfire counts, and fuel trims before clearing.
- Inspect ignition system: Replace spark plugs if overdue, swap coils, and test for injector pulse and fuel pressure.
- Check for intake/EVAP leaks: Smoke-test the intake manifold, inspect PCV hoses, and test EVAP purge valve for proper sealing.
- Clean throttle body and relearn: Remove carbon buildup, perform an ETC relearn (key-on/engine-off procedures), and update software if necessary.
- Evaluate fuel trims: After repairs, monitor STFT/LTFT during idle and cruise to ensure they fall within ±10%.
- Perform validation drive: Clear codes, complete a city/highway drive, and verify idle smoothness with no pending or permanent DTCs.
Driving Guidance During Diagnosis
- Avoid long idle periods and heavy loads while misfire or fuel-trim codes are active.
- Drive gently after throttle body cleaning or ETC relearn to stabilize adaptives.
- Monitor coolant temperature and oil pressure; abnormal readings warrant immediate attention.
Preventive Maintenance Tips
- Replace spark plugs at 60,000 miles and inspect coils for tracking.
- Perform throttle body cleaning and idle relearn annually to prevent carbon-related idle issues.
- Inspect PCV valve, intake manifold gaskets, and purge hoses during each service interval.
- Replace the fuel filter/clean injectors at manufacturer intervals to maintain proper spray pattern.
- Change oil every 5,000–6,000 miles to preserve actuator and VVT operation.
Frequently Asked Questions
Can I clear the light before fixing the rough idle?
No. Clearing codes without repairs only hides the issue temporarily. The MIL returns once the PCM reruns diagnostics.
No. Rough idle and misfire codes need physical repairs—premium fuel will not solve them.
How long should I drive after repairs?
Drive about 50 miles with mixed conditions to confirm the idle is smooth and readiness monitors are COMPLETE.
Related Charger Resources
- Durango misfire workflow.
- Transmission diagnostics if limp mode appears.
- Ignition/no-spark diagnostics.