Long Term Fuel Trim Mixture Too Rich
2015-2021 Kia Sedona 3.3L V6
Description
The PCM has detected that the long-term fuel trim is correcting excessively in the lean direction, indicating the engine is running too rich. The fuel system is consistently delivering more fuel than needed.
Symptoms
- Check Engine Light
- Poor fuel economy
- Black smoke from exhaust
- Rough idle
- Fouled spark plugs
Common Causes
- Leaking fuel injector
- High fuel pressure (faulty regulator)
- Faulty oxygen sensor reading lean incorrectly
- Saturated charcoal canister purging fuel vapor
- Coolant temperature sensor reading cold
Diagnostic Steps
- Check long-term fuel trim values on scan tool (excessively negative indicates rich correction)
- Check fuel pressure with gauge
- Inspect spark plugs for rich fouling
- Test O2 sensor operation
- Check for leaking injectors
Repair Notes
Correct the root cause of the rich condition, typically a leaking injector or faulty fuel pressure regulator.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1123 on Other Vehicles
Common Questions
What does code P1123 mean on a 2015-2021 Kia Sedona?
P1123 stands for "Long Term Fuel Trim Mixture Too Rich". The PCM has detected that the long-term fuel trim is correcting excessively in the lean direction, indicating the engine is running too rich. The fuel system is consistently delivering more fuel than needed.
What are the symptoms of P1123 on a Kia Sedona?
Common symptoms of P1123 include: Check Engine Light, Poor fuel economy, Black smoke from exhaust, Rough idle, Fouled spark plugs.
What causes P1123 on a 2015-2021 Kia Sedona?
Common causes of P1123 include: Leaking fuel injector, High fuel pressure (faulty regulator), Faulty oxygen sensor reading lean incorrectly, Saturated charcoal canister purging fuel vapor, Coolant temperature sensor reading cold.