Code P0171

You could have them check the upper O2 sensor.

A code P0171 indicates the engine is running lean. This means there is too much air and/or not enough fuel. You can confirm the engine is running lean by looking at Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). Normally, STFT and LTFT should be plus or minus 5 to 10 from zero. If STFT and/or LTFT are more than about +12, it indicates the engine is running lean. Negative numbers (-12 or more) indicates the engine is running rich.

A lean fuel condition can be caused by:

* O2 sensors-low voltage

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

Good Luck

A code P0171 indicates the engine is running lean. This means there is too much air and/or not enough fuel. You can confirm the engine is running lean by looking at Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). Normally, STFT and LTFT should be plus or minus 5 to 10 from zero. If STFT and/or LTFT are more than about +12, it indicates the engine is running lean. Negative numbers (-12 or more) indicates the engine is running rich.

A lean fuel condition can be caused by:

* O2 sensors-low voltage

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

BTW what was the code on No.6 CEL

Good Luck[/quote:c2993176b2]

Wow hard to believe the dealer missed the most common cause of this code on this vehicle, especially since honda has a tsb on it. Most common problem for this is the fuel pressure regulator and the vacuum hose going to it.

There is an updated fuel pressure regulator kit