Symptom hub
Poor Fuel Economy: DTC Patterns to Check First
Poor MPG often overlaps with fuel trim, oxygen sensor, thermostat, airflow, and catalyst efficiency issues.
Likely related codes
Start your diagnostic path here
P0172 — System Too Rich (Bank 1) P0420 — Catalyst System Efficiency Below Threshold (Bank 1) P0430 — Catalyst System Efficiency Below Threshold (Bank 2) P0103 — Mass or Volume Air Flow Circuit High Input P0104 — Mass or Volume Air Flow Circuit Intermittent P0101 — Mass Air Flow Circuit Range/Performance P0110 — Intake Air Temperature Sensor 1 Circuit Malfunction P0111 — Intake Air Temperature Sensor 1 Circuit Range/Performance P0113 — Intake Air Temperature Sensor 1 Circuit High Input P0114 — Intake Air Temperature Sensor 1 Circuit Intermittent P0115 — Engine Coolant Temperature Circuit Malfunction P0116 — Engine Coolant Temperature Circuit Range/Performance P0118 — Engine Coolant Temperature Circuit High Input P0119 — Engine Coolant Temperature Circuit Intermittent P0125 — Insufficient Coolant Temperature for Closed Loop Fuel Control P0128 — Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) P0133 — O2 Sensor Circuit Slow Response (Bank 1 Sensor 1) P0155 — O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1) P0175 — System Too Rich (Bank 2) P0170 — Fuel Trim Malfunction (Bank 1) P0173 — Fuel Trim Malfunction (Bank 2) P2192 — System Too Rich at Higher Load (Bank 1) P2096 — Post Catalyst Fuel Trim System Too Lean (Bank 1) P2097 — Post Catalyst Fuel Trim System Too Rich (Bank 1) P2098 — Post Catalyst Fuel Trim System Too Lean (Bank 2) P2099 — Post Catalyst Fuel Trim System Too Rich (Bank 2) P2270 — O2 Sensor Signal Stuck Lean (Bank 1 Sensor 2) P2271 — O2 Sensor Signal Stuck Rich (Bank 1 Sensor 2) P2272 — O2 Sensor Signal Stuck Lean (Bank 2 Sensor 2) P2273 — O2 Sensor Signal Stuck Rich (Bank 2 Sensor 2) P00BD — Mass or Volume Air Flow A Circuit Range/Performance - Airflow Too High P0400 — Exhaust Gas Recirculation Flow Malfunction P0404 — Exhaust Gas Recirculation Circuit Range/Performance P0406 — Exhaust Gas Recirculation Sensor A Circuit High P0183 — Fuel Temperature Sensor A Circuit High Input P219A — Bank 1 Air/Fuel Ratio Imbalance P219B — Bank 2 Air/Fuel Ratio Imbalance P0232 — Fuel Pump Secondary Circuit High P0629 — Fuel Pump A Control Circuit High P0408 — Exhaust Gas Recirculation Sensor B Circuit High P0488 — Exhaust Gas Recirculation Throttle Control Range / Performance P2279 — Intake Air System Leak P2177 — System Too Lean Off Idle Bank 1 P2179 — System Too Lean Off Idle Bank 2 P1128 — Closed Loop Fueling Not Achieved Bank 1 P1129 — Closed Loop Fueling Not Achieved Bank 2 P1174 — Fuel Trim Cylinder Balance Bank 1