P0171

DTC P0171: Rear Bank (Bank 1) Fuel System Too Lean

NOTE: If some of the DTCs listed below are stored at the same time as DTC P0171, P0172, P0174, and/or P0175, troubleshoot those DTCs first, then recheck for P0171, P0172, P0174, and/or P0175.

P0107, P0108, P1128, P1129: Manifold absolute pressure (MAP) sensor
P0133, P0153, P2195, P2197, P2237, P2238, P2240, P2241, P2243, P2245, P2247, P2249, P2251, P2252, P2254, P2255, P2627, P2628, P2630, P2631, P2A00, P2A03: Air fuel ratio (A/F) sensor (Sensor 1)
P0134, P0135, P0154, P0155: Air fuel ratio (A/F) sensor (Sensor 1) heater
P0137, P0138, P0139, P0157, P0158, P0159: Secondary HO2S (Sensor 2)
P0141, P0161: Secondary HO2S (Sensor 2) heater
P2646, P2647, P2648, P2649: VTEC system
P0401, P0404, P0406, P2413: Exhaust Gas Recirculation (EGR) system
P2279: Intake air leakage

1. Check the fuel pressure.

Is the fuel pressure OK?

YES - Check the valve clearances and adjust if necessary. If the valve clearances are OK, replace the injectors, then go to step 2.

NO - Check these items:

- If the pressure is too high, replace the fuel pressure regulator, then go to step 2. If the pressure is too low, check the fuel pump, and the fuel feed pipe, then go to step 2.

2. Turn the ignition switch ON (II).
3. Reset the ECM/PCM with the HDS.
4. Do the ECM/PCM idle learn procedure.
5. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
6. Test-drive under these conditions:

- Engine coolant temperature more than 158 °F (70 °C)
- A/T in D position (M/T in 5th gear)
- Drive at a steady speed between 25 - 55 mph (40 - 88 km/h) for 5 minutes, then drive at a steady speed between 15 - 75 mph (24 - 120 km/h) for 15 minutes.

NOTE: DTC P0171, P0172, P0174, and/or P0175 may take up to 40 minutes of test driving to set. Use the HDS to monitor the AF FB AVE for 15 minutes of driving. If the AF FB AVE stays within 10% of 1.0 (0.0 %),there is no problem at this time.

7. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0171, P0172, P0174, or P0175 is indicated, go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.