The DTC indicates that the oxygen sensor on the first cylinder bank has detected lean engine conditions. This means that there is too much air or not enough fuel in the system. The ECU adjusts the air-fuel mixture based on the sensor readings to achieve the optimum ratio (14.7). If it is unable to maintain the correct ratio by injecting more fuel, the computer will register this code. P0171 is often accompanied by P0174 (System Too Lean Bank 2).
Common causesBefore tackling repairs, the very first thing you will need to do is a diagnostic scan. You can scan the computer using an OBD2 scanner and check the related trouble codes. This will not only help you to identify the root cause of the fault, but could also reveal other hidden problems.
Depending on what you find, the following components may need to be inspected:
Once you have obtained a proper diagnosis, you can repair the units by cleaning, tightening, and replacing the faulty components. Don’t forget to check the gaskets too as they may need to be replaced to fix or prevent leaks.
It indicates that there is too much air in the fuel mixture, causing the engine to operate inefficiently.
It is often caused by problems with the components in the fuel injection and exhaust systems. The mixture process is easily affected when there are leaks, components are clogged, and power supply components are unreliable.
This is strongly advised against as a lean fuel mixture can wreak havoc on the engine, causing thermal damage to gaskets and valves. Consulting a professional and getting the car fixed as soon as possible is the best way to avoid further damage and expensive repairs.
It can be cleared properly after the problem has been rectified. All you need to do is connect the OBD2 scan tool to the car via the data link connector and erase the fault codes from the computer’s memory archive.
Fault code P0171 - System Too Lean (Bank 1) can occur with any car but is most often found on the following cars:
If you get the code P0171 on your car, make sure that the diagnostics are carried out correctly and the error is still relevant. Check for symptoms associated with the problem and explore options for resolving it.
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