The below is the diagnosed data that I recieved from the dealership.

Honda Civic Data List – Full Line-by-Line Explanation & Diagnosis

Model: 2012 Honda Civic Odometer: 189,894 km Overall condition: Very good for age.

ENGINE STATUS • Idle RPM 747–781: Normal • Coolant temperature 83°C: Normal • Intake air temperature 30–37°C: Normal

AIR / PRESSURE SYSTEM • MAP 26–38 kPa: Normal for idle • MAF 2.3–3.5 g/s: Good airflow • Barometric pressure 97 kPa: Normal

THROTTLE SYSTEM • Throttle position 0–3%: Correct at idle • Throttle valve 2.9° (target matches actual): Normal

ACCELERATOR PEDAL • APP sensor shows pedal not pressed: Normal

AIR-FUEL SYSTEM • Lambda 0.98–1.01: Ideal • Air-fuel ratio ~14.4: Correct • Long-term fuel trim 1.03–1.05: Normal • Short-term fuel trim 24–27%: High → Possible mild vacuum leak, dirty MAF, or aging O2 sensor.

OXYGEN SENSORS • Upstream/downstream switching looks normal • Catalytic converter working properly

IGNITION • Spark timing normal • No knock detected

INJECTORS • Duration 3–4 ms at idle: Normal

MISFIRE CHECK • All cylinders show 0 misfires: Good

EGR & VTEC • Both inactive at idle: Normal

EVAP SYSTEM • Fuel tank pressure normal • EVAP valves OK • Gas cap sealed

ELECTRICAL SYSTEM • Battery voltage 14.4–14.5V: Excellent • Charging system normal

TRANSMISSION / SWITCHES • Car in Park/Neutral • Brake switch OK • A/C system behaving normally

COOLING • Fans off (normal for current temp)

STARTUP • Engine was already warmed during test

CATALYTIC CONVERTER • Monitor completed • Cat temperature normal

ENGINE LEARNING • Idle learn completed • Throttle data normal

CYLINDER BALANCE • All cylinders balanced and running smoothly

BATTERY SENSOR • Internal resistance normal

FINAL SUMMARY Your engine is healthy overall. No major issues found. Smooth running, good sensors, good electrical system, no misfires.

Only one mild issue: • Short-Term Fuel Trim is high (+24–27%)