Audi A4 Trouble Codes, Symptoms & Recalls
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Common check engine codes on the Audi A4
- P0420 — Catalyst System Efficiency Below Threshold (Bank 1)
- P0300 — Random/Multiple Cylinder Misfire Detected
- P0171 — System Too Lean (Bank 1)
- P0442 — Evaporative Emission System Small Leak Detected
- P0455 — Evaporative Emission System Large Leak Detected
- P0128 — Coolant Temperature Below Thermostat Regulating Temperature
- P0401 — EGR Insufficient Flow Detected
- P0440 — Evaporative Emission Control System Malfunction
- P0301 — Cylinder 1 Misfire Detected
- P0174 — System Too Lean (Bank 2)
Common Audi A4 symptoms
- Audi A4 car shaking when braking
- Audi A4 brakes squealing when stopping
- Audi A4 check engine light on
- Audi A4 car won't start
- Audi A4 car overheating
- Audi A4 car loses power when accelerating
- Audi A4 car running or idling rough
- Audi A4 white smoke from exhaust
- Audi A4 blue smoke from exhaust
- Audi A4 battery light on while driving
- Audi A4 car pulls to one side
- Audi A4 car ac not blowing cold
Maintenance & recalls
Audi A4 maintenance resources · Audi A4 NHTSA recalls & complaints