Had new Mass airflow sensor put on an now I’m getting a code p0171 what could it be

in the morning I start it up an it start putting an shut off but starts back up gotta put it in drive when warming up

My car has 158000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
This relates to a lean fuel condition which can be caused by many different things such as:

Intake air leaks
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Airflow (MAF) sensor (You already replaced, so it should not be this)
Incorrect Positive Crankcase Ventilation (PCV) hose connection

I would recommend having an expert from YourMechanic come to your home to diagnose your trouble code firsthand and help you repair it as necessary.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

The mass air flow (MAF) sensor measures the amount of air entering the engine. Check engine light code P0101 is set when the measurement of air entering the engine by the mass air flow sensor is outside of the manufacturer`s specified range.
A faulty mass airflow sensor is a common reason why a check engine light comes on. If the engine control module receives a MAF error code, it will turn on the check engine light to let you know that there is a problem with the engine.
an “under reporting” mass air flow sensor can be a common cause of a code p0171. essentially, this means that the air flow sensor is telling the computer that much less air is entering the engine than actually is.
The P0171 refers to a possible lack of fuel pressure, a leak in the intake air system, or a possible vacuum leak.
Error code P0101 indicates that there is an issue with your mass airflow sensor (MAF).
The MAF sensor malfunctioning can also cause your car to throw a check engine light (CEL). Furthermore, it can cause different check engine codes such as the O2 sensor, “low air volume”, or something else.
A P0171 code is set by your vehicle`s powertrain control module (PCM) when it detects that the air-to-fuel ratio of your vehicle is too lean. This means that the PCM is relaying that the engine is receiving too much air into the combustion chamber and not enough fuel.
What Does P0171 and P0174 Mean? DTCs P0171 and P0174 are generic codes that set when the feedback on the engine`s air/fuel mixture becomes too lean for the Engine Control Module (ECM) to correct within its normal operating range. A lean mixture is a mixture that has too much air or not enough fuel.
The OBD code P1101 is a trouble code that appears when the Power Control Module (PCM) detects a fault within the Mass Air Flow (MAF) sensor system. When this code sets, the PCM detects a discrepancy with the voltage readings coming from the MAF sensor.
The reading is too lean (i.e. too much air or not enough fuel). P0171 is a bank one reading lean, P0172 is for bank two reading lean. If the PCM is saying is that the sensor cannot be sense, that would be a different code.
The air filter may be the MAF sensor`s first line of defense via the engine`s air intake system, but a clogged, low quality or dirty air filter can actually become the source of MAF sensor damage if any contamination bypasses it.
The OBD code P1101 is a trouble code that appears when the Power Control Module (PCM) detects a fault within the Mass Air Flow (MAF) sensor system. When this code sets, the PCM detects a discrepancy with the voltage readings coming from the MAF sensor.
What Does Code P0102 Mean? Your MAF sensor is typically installed downstream from your air filter on your air intake tract. It measures both the density and volume of air passing through your intake and into the engine. A P0102 error code means that there`s insufficient air traveling through your air filter.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I put a cold air intake on my car I have replace the O2 sensor that is failing area code p0151 I’m not sure what to do mass is new
ANSWER : Hello. If the P0151 code persists after replacing the oxygen sensor, then it may be possible that the issue is with the wiring. If there is any damage or wear to the oxygen sensor connector or wiring there may be a compromise in the voltage, which can set off the light. I would carefully examine the wiring and connector for any signs of damage or wear. If the issue began only after installing the cold air intake, it may also be possible that the issue is related to the cold air intake. If you think that may be a possibility, I would try reinstalling the stock cold air intake to see if that may solve the issue. For in-depth help diagnosing the code, consider enlisting an expert from YourMechanic to come to your for an inspection.

Had new Mass airflow sensor put on an now I’m getting a code p0171 what could it be
ANSWER : This relates to a lean fuel condition which can be caused by many different things such as:

Intake air leaks
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Airflow (MAF) sensor (You already replaced, so it should not be this)
Incorrect Positive Crankcase Ventilation (PCV) hose connection

I would recommend having an expert from YourMechanic come to your home to diagnose your trouble code firsthand and help you repair it as necessary.

I had a p0405 get code replaced egr valve, map sensor,mad sensor, and PCv valve just to be safe but still getting the code why?
ANSWER : The code P0405 and a rough idle is most likely due to carbon getting into the EGR pintle. This will hold the EGR open. When you are getting the rough idle you should shut off engine and remove EGR valve. Check to see if carbon is holding the pintle open. If it is then you will have to remove the carbon from the pintle. Then try and clean out the EGR passages by scrapping them using a round wire brush. Afterwards, start the engine for a few seconds with valve removed to blow out loose carbon. You should then spray a small amount of carbon cleaner into the passages to dissolve the carbon. Lastly, reinstall the EGR and reset the light and codes.

If you’d like assistance with this, consider YourMechanic, as a certified professional can come to the vehicles locations to perform these checks and properly diagnose your Check Engine Light.

My code reader says I have a bad mass air flow sensor ans crank shat sensor test drive ran better shut off & engine Lt. Same code
ANSWER : Hi there. The problem you are describing, sounds like you may have a poor connection in the connector at the mass airflow sensor. Although, sometimes aftermarket parts do not perform as well as factory (OEM) parts. Check for corrosion and/or wide spacing in the terminal ends. Compare the terminal ends in the connector using a flashlight to see better. The terminals can be tightened. If you are not comfortable with doing that, a replacement pigtail (connector) is available. You vehicle may require further diagnosis performed with a scanner that provides parameters that can be viewed as the fault occurs. If that is the case, I recommend having your vehicle’s electrical circuits inspected in order to pinpoint the underlying fault.

P0140, P0191, P2000. I put a new oxygen sensor in
ANSWER : Hi there. These codes are coming on for a possible fuel pressure issue that could also be causing the catalytic converter to burn too hot. Check the fuel rail pressure and make sure that the pressure does not exceed minimum pressure of 4,000. Careful with checking the pressure, the rail can produce pressures up to 26,000 psi.

Make sure that you use a gauge that can handle very high pressure. Check the fuel rail pressure sensor for resistance with the engine running. If the resistance is not moving when throttling the engine, then the fuel fail pressure sensor needs replaced. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can pinpoint the cause for each code and proceed with proper adjustments or repairs.

cold rough idle and P0303 code , run great after clearing code and warming up,
ANSWER : Code P0303 suggests a misfire in cylinder #3. This can happen for many reasons such as a vacuum leak, weak fuel pump (pressure), bad ignition coil, low voltage to the fuel injectors (causing pulse problems) or a faulty mass air flow sensor, all of which can cause an imbalance in the air/fuel charge in that cylinder. Try checking to see if you are able to replicate the misfire and see if it happens more under load or at idle or if it is completely just intermittent. This may help to narrow down what types of components to check.

check engine light O2 sensor already replaced same codes still popping up after replacing old O2 sensor
ANSWER : Hi there. What you received from the parts store was a code retrieval, not a diagnostic. The codes are set when a fault is detected against normal operating parameter. The computer does not know what caused the fault, only that the fault meets the criteria for this code to set. There could be a problem in the wire harness, converter, or the ECM. The code and data are needed to properly assess the direction that a diagnosis needs. I strongly suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a check engine light inspection.

my car is slow to accelerate. i have a p0171 code. i replaced my o2 sensor but the code came back on. what else could it be?
ANSWER : The code P0171 is a lean code indicating the O2 sensor is detecting the engine is running lean – that is, the air/fuel mixture is imbalanced. You may have a clogged fuel filter or a fuel pump that is not supplying enough fuel pressure. You will need to have the fuel pressure and volume checked with a fuel pressure gauge. You can try to replace the fuel filter to see if it helps first. Your best thing to do is to have a mechanic diagnose the problem and check the fuel pressures and filter. Also make sure your air filter is clean and the inlet air tube is not cracked or loose.

Check these items, and if you still need assistance, contact a professional mechanic. A certified mobile mechanic from YourMechanic can visit your home or office to inspect your vehicle’s acceleration issues.