Consult your service manual for it's location if you need help. I didn't see the post above about the O2 sensor, will a bad O2 sensor through a code for an O2 sensor, or just one like P0171? Fix any wiring problem before continuing. The check engine light still come on. Also, check the air intake hose looking for any sign of deterioration or leak. Meanwhile, you will experience symptoms like bad fuel economy, rough idle, Check Engine warning light, weak acceleration, and engine stalling.
However, I do not see this one very often causing this code. If the light lit during your driving cycle then continue with the diagnostic process. Look for burnt, damaged, corroded or deteriorated wires, also unplug the sensor and look for bent terminal pins, loosely connections, corrosion or any other possible indication of a bad connection. What if the engine had plugged fuel injectors or if one of the sensors on your engine was bad not allowing enough fuel into the engine while it was running? Not enough fuel for a given amount of air or too much air for a given amount of fuel. If you also have any other code related to the ignition system, emissions system or fuel system then you should start diagnosing them first. Based on the data, the engine control unit decides whether to inject more fuel or less fuel into the chamber. You may find that sometimes all the above components are in good condition but the code P0171 is still present.
If the valve timing has jumped, then the engine vacuum will be a bit lower than normal at idle. I have tried everything, but I am coming to the conclusion that I have a bad pcv letting in too much air. Injectors werent giving enough fuel to the engine. If there are still issues after inspecting all of the components in this article, take the engine to your mechanic for more detailed investigations. The cars computer determines injector pulse width based on the inputs it receives from various sensors.
The Engine Control Module calculates the necessary compensation to correct the offset between the actual and the theoretical ratios. I haven't scanned it yet to see which code it is, but I imagine that it is P0171. If the problem persist the front oxygen O2 sensor may need to be replaced. I have a 1998 F150 5. If there are no intake leaks, the next step is to replace the air filter and clean the air flow meter. It would run lean and will definitely cause your P0171 diagnostic trouble code. Another possible cause is from … low fuel pressure due to restricted fuel lines or a bad fuel pump.
This will prevent the cylinder from getting all of the air in needs for the combustion process and will result is a lean condition. If there are no intake leaks, the next step is to replaced the air filter and clean the air flow meter. Ideally, you want it to run right in the middle. They're only like 8-12 dollars at an autoparts store Symptoms. Alternatively, if there is very little fuel and an abundance of oxygen in the chamber, it will cause trouble code P0174 to generate instead. The mixture ratio is too lean.
Does anyone know what the voltage should be on the O2 sensors? Check the in-line fuel filter and the tank fuel filter element. Don't touch it or probe it, just spray inside it and let dry before reinstalling. I had the code P0171 on a Ford Contour 1998 2. These leaks could result in the wrong quantity of air making it to the cylinders for combustion. Without a scan tool, the only way to find the problem is to check the basics and research common problems with your particular car make, year and model. You may even experience misfiring on multiple occasions. Engines with timing chains will usually not jump time.
It is also possible that the engine will appear to be operating normal. In case the Check Engine Light stays off then you may have an intermittent problem. Also check your fuel filter you might as well just replace the fuel fiter. It is a bit expensive, but i will save you a tone of time. Dodge Jeep and Chrysler: Air or vacuum leak or. Read more about using a scan tool.
This is a very important step! P0174, fuel system too lean, bank 2, can be a serious issue. It is very important that the engine vacuum remain steady at idle. In addition, if you get one, you can make a couple of bucks smoke checking your friends and families Evaporative Emissions and intake systems when the time comes. If you have an air or a vacuum leak, would the engine run lean? If the problem persistss the front oxygen O2 sensor may need to be replaced. But again, this is just one side of it. P0174 Symptoms The first indication of the problem should be a light on the dash, although that may not always be the case. If it is bouncing around or going up and down slightly as the engine is idling, then you could have a mechanical issue or even an air or a vacuum leak like we talked about earlier.