What is code P171?
The P0171 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. A lean condition occurs when the engine either receives too little fuel or too much air.
What to do if your check engine light code is p0171?
Reconnect any disconnected vacuum lines and replace any damaged vacuum lines that are leaking, then use FIXD to clear check engine light code P0171. If check engine light code P0171 is triggered again, check the rest of the vacuum lines for leaks and continue to the rest of the diagnostic process.
What does p0171 and po174 mean?
A continual low voltage reading indicates a lean fuel mixture, too much oxygen. The optimal ratio is 14.7:1 (air:fuel). When your powertrain/engine control module receives a reading that indicates there’s too much oxygen and the ratio is incorrect, it sends an error code P0171 or P0174.
Where is the p0171 sensor located on a Chevrolet Cruze?
Where is the P0171 sensor located? There are far too many examples of vacuum leaks on Chevrolet engines to list here, but one engine in particular, the 1.4L gasoline engine fitted to Chevrolet Cruze and related applications deserves a special mention. The valve cover from such an engine is shown below-
What causes p0171 fuel trim to be too lean?
Even if all the bolts are torqued down to specified values, the gasket between the valve cover and the cylinder head is prone to shrinkage and failure, allowing unmetered air to enter the engine, which causes P0171 to set. There is no known, reliable remedy for this issue, except to replace the gasket with an OEM part when it fails.
What to do if check engine light code p0171 is triggered?
If check engine light code P0171 is triggered again, check the rest of the vacuum lines for leaks and continue to the rest of the diagnostic process. Remove the mass airflow sensor and clean the sensor using mass air flow cleaner or contact cleaner.
A continual low voltage reading indicates a lean fuel mixture, too much oxygen. The optimal ratio is 14.7:1 (air:fuel). When your powertrain/engine control module receives a reading that indicates there’s too much oxygen and the ratio is incorrect, it sends an error code P0171 or P0174.
When to set the Check Engine Light code?
Please refer to our article Oxygen Sensor Code Diagnosis for more info on this system. A P0171 check engine light code is set when the computer has reached a rich calibration limit and can not add enough fuel to maintain the correct mixture.
What causes the p0171 code on a Ford TSB?
Another Ford TSB for a number of late 90-s Ford vehicles describes a problem with MAF sensor contamination where both codes, P0171 and P0174 would appear together. Problems with the mass air flow (MAF) sensor causing the code P0171 are fairly common in many vehicles.