If an engine runs improperly for a long period of time, further damage may result that could end up being much more costly to the owner of the vehicle. It is unwise to drive a vehicle with this trouble code stored for a long period of time. Replacing the powertrain control moduleĪdditional comments regarding the P0171 code.It is a good idea to have this code diagnosed and repaired as soon as possible to have your vehicle running smoothly. If the engine does not maintain proper air/fuel ratio, there will be a major waste of fuel and a lack of power while driving. If a vehicle has this code stored in its powertrain control module, the engine of that vehicle simply will not run well. They can save you a world of time and effort. If all of these tests have been performed and no issues are found, the problem is likely the powertrain control module.Ĭommon mistakes when diagnosing the P0171 codeĪ mistake that often occurs is not looking for any technical service bulletins for your specific car model that may be related to this issue.Īlthough not every trouble code will have a technical service bulletin associated with it, it is always wise to check. The mechanic would then run tests on the mass airflow sensor and the oxygen sensors using the manufacturer’s procedure. If the cause of this issue is still not found after the mechanic has performed these two tests, the problem likely lies with a sensor. The cause of this trouble code will likely be discovered during one of these two tests. In order to maintain a proper air/fuel ratio, the vacuum and fuel pressure of the engine must be within the manufacturer’s specifications. The fuel pressure sensor and MAF sensor (mass air flow) will also be checked with a fuel pressure gauge.

A vacuum leak will create a hissing sound usually only audible when the engine is turned off. How does a mechanic diagnose the P0171 code?Īssuming that no other trouble codes exist, a mechanic may diagnose the P0171 code by checking the engine for vacuum leaks with a vacuum gauge. Catalytic converter damage may result if this code is stored for a long period of time.A lean condition occurs when the engine either receives too little fuel or too much air. The P0171 OBD-II code means that, on the first bank of the engine, the fuel system is running weak or a vacuum leak exists near this side of the engine. System Too Lean (Bank 1) What the P0171 code means

Mazda 6 p0171