Q: Here is the code to the check engine light, P0171- System Too Lean Bank 1

asked by on February 10, 2018

Here is the code to the check engine light, P0171- System Too Lean Bank 1
I already fixed the sensors recently and also checked to see if their was a leak. a few months back which the results were negative. I think I need to replace my air filter housing,
My car has 98619 miles.
My car has an automatic transmission.

A number of things may cause code P0171 or P0174 to be triggered. As the codes indicate, this means there is a lean fuel condition which may be caused by a lack of fuel supply or in some cases, a vacuum leak. These codes are also often times associated with misfire codes as well. When a vacuum leak is present, this introduces an excessive amount of air into the fuel/air mixture which results in leaning out the fuel content. Other problems such as a faulty fuel pressure regulator, a faulty fuel pump, a clogged fuel filter, faulty fuel injectors, faulty oxygen sensors, or a faulty mass air flow sensor may also cause this to happen. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Power steering loss
Hi there, thanks for writing in about your 2001 Mercedes Benz ML430. This problem could be caused by a slipping belt (https://www.yourmechanic.com/services/drive-belt-tensioner-replacement) or a faulty belt tensioner (https://www.yourmechanic.com/services/drive-belt-tensioner-replacement). The power steering pulley needs to be observed while the car is...
How long should it take a mechanic to replace the a/c compressor on my 06 E 150 4.6
The a/c compressor replacement (https://www.yourmechanic.com/services/ac-compressor-replacement) will not be the only component that will need to be replaced at the same time. The replacement of the compressor is about 1.5 hours and does not include the recover or evacuate and recharge...
My temperature gauge keeps making it look like my car is overheating the temperature gauge moves up to the red. I already changed the thermometer
Hey there. Your cooling system consists of several components. Thermostat, radiator, heater core, and water pump are just a few. Since the thermostat has been replaced, it is more than likely not the cause of the engine running hot. If...
Battery light just came on. What could it mean? Is it safe to drive?
This may be a sign of a weak battery, a failing voltage regulator or failing alternator. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while...
Transmission pan leak
Hello. If the gasket and sealant were applied and allowed to cure properly then you should not need to shift the pan in any sort of way. If the gasket is leaking then re torquing the bolts may repair the...
Headlight on the passenger side keeps going out. Have replaced the bulb and the ballast.
Hi there. Check the harness to the headlight with the headlight switch on and see if there is a voltage present. If there is a voltage, then check for resistance on the ground side of the harness. If there is...
changed electronic throttle body, wrench lights when stopping hard and taking off fast, lose power
Hi there. The wrench light is a service indicator light that is designed to alert the driver that routine service or maintenance is required. In some cases, this light is illuminated when excessive carbon is detected in the fuel system....
Changed alternator and battery now car makes a noise when you start it up
This is a common sign of a loose or worn belt. This may have happened when you replaced the alternator potentially tightening the belt too tight. When this happens as you press the gas pedal and the belt goes from...

Related articles

A Buyer’s Guide to the 2012 Hyundai Genesis
The The 2012 Hyundai Genesis is a midsize luxury sedan that is both powerful and well equipped with lots of standard features. It has an elegant look with the choice between V6 or two V8 engines. This four door sedan...
A Buyer’s Guide to the 2012 Toyota Sienna
The The 2012 Toyota Sienna is one of the most innovative and luxurious minivans on the market today. Not only has Toyota increased its size to better compete with the Dodge Grand Caravan and the Honda Odyssey, but you can...
The Best Used Cars to Buy If You're a General Contractor
If If you're a general contractor, you probably aren’t in the market for a used car. More likely, you’re looking for a pickup truck, because you need to haul equipment and supplies to various job sites. Most contractors will likely...