P0171 & P0174 can also be a bad DISA valve (or leaking seals around the DISA). Pull it out & check for the pin. If that one falls in the engine, it ruins it. GAS has a repair kit for failing DISA. Check the big rubber boot around the "Y" for torn spots. Check the CVV for broken plastic hoses, O-ring around the dipstick.

Also, the problems that usually trigger the P0171 and P0174 Code are:
PCM software needs to be updated.
Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.)Mass Airflow Sensor (MAF)
Plugged Fuel Filter or weak Fuel Pump
Plugged or dirty Fuel Injectors
Don't fall for Oxygen sensors.

For a quick test, try the carb cleaner spray around the spots mentioned above to check (car idling).
For a more detailed procedure and if you have a decent scanner (like GT1) monitor the fuel trim (short & long).
To check the MAF for inaccurate readings, unplug it with the engine running. No change in idle, it's toast. Or you can do it the proper way by reading the barometric pressure on the scan tool. If the barometric pressure readout is at high elevations, and you are at sea level or close, the MAF is toast (or needs cleaning if you're lucky).

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Stable: e92is, e46 M54B25, e83 N52, e53 N62 - sold, e39 M54B30 R.I.P.