Rough Idle: OBD2 Diagnosis Path

Idle vibrations, unstable RPM, and engine stumble when stopped. Start with the related code pages below, then use scanner and guide pages to narrow down root cause and reduce unnecessary parts swaps.

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Most Related OBD2 Codes

P0171 · System Too Lean (Bank 1) P0300 · Random / Multiple Cylinder Misfire P0507 · Idle Air Control System RPM High P0401 · Exhaust Gas Recirculation Flow Insufficient Detected

Related Scanner Intent Pages

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Tip: if your exact code is still unknown, start at OBDHacks scanner input and then return to this symptom cluster for deeper troubleshooting.