Fault Codes/Discovery Energy, LLC (Rehlko)/P0171Discovery Energy, LLC (Rehlko)P0171WarningGeneralWhat This Code MeansP0171Possible Causes•Problem with fuel delivery or fuel feedback control or an overheated HEGO sensor.Suggested Actions1Check for other DTC codes or misfires.2Check for exhaust leaks ahead of or near the HEGO sensor.3Check fuel system for restrictions.4Check fuel pressure regulator.5Check fuel shutoff valve.6Confirm fuel quality and fuel pressure.Related Discovery Energy, LLC (Rehlko) Fault CodesP0172P0335P0121P0508P0118P0509P0117P0563P0116P0603P0113P0604Browse all Discovery Energy, LLC (Rehlko) fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for P0171 on your specific Discovery Energy, LLC (Rehlko) unit — cited to the OEM manual, not a forum guess.Your question about P0171GET THE ANSWERFree account required — we'll bring your question with you.