Skip the auto shop - Our mechanics make house calls

P0174 OBD-II Trouble Code: System Too Lean (Bank 2)

Check Engine Light

P0174 code definition

System Too Lean (Bank 2)

What the P0174 code means

Code P0174 indicates that there is a lean condition detected by the Engine Control Module (ECM). A lean condition will be created if there is too much air, and not enough fuel, in the air fuel ratio (AFR). The ECM is designed with the capability of adjusting a lean condition back to normal, but only in small to mediocre amounts. If the air fuel ratio requires more compensation to return to normal than the ECU is capable of, code P0174 may set.

What causes the P0174 code?

  • An air leak after the mass air flow (MAF) sensor, such as a torn intake boot, or bad intake manifold gaskets
  • A dirty or faulty mass air flow sensor
  • Faulty oxygen sensor
  • Incorrect fuel pressure
  • Leaking positive crankcase ventilation (PCV) valve
  • Clogged exhaust gas recirculation (EGR) Port
  • Leaking brake booster

What are the symptoms of the P0174 code?

  • Increased fuel consumption
  • Check Engine Light will come on
  • Rough or high idle
  • Decreased acceleration
  • Engine stalling

How does a mechanic diagnose the P0174 code?

  • Performs a fuel pressure test
  • Checks the intake system and vacuum lines for leaks
  • Inspects the valve cover for worn hoses or leaks
  • Inspects the PCV valve
  • Tests the mass air flow sensor with a scan tool or multimeter
  • Tests the related oxygen sensor with a scan tool or multimeter

Common mistakes when diagnosing the P0174 code?

  • Replacing a component without first deeming it bad through testing
  • Failing to check the intake system for tears or leaks

How serious is the P0174 code?

Generally, a lean condition is not that serious. However, be aware that there is a possibility of the lean condition being caused by a leak in the intake system. Leaks in the air intake may allow particles to enter the engine, which may be damaging.

What repairs can fix the P0174 code?

Additional comments for consideration regarding the P0174 code

Be sure to check the intake manifold and vacuum lines for leaks.

Need help with a P0174 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P0359 OBD-II Trouble Code: Ignition Coil I Primary/Secondary Circuit Malfunction
P0359 code definition The P0359 code indicates that a fault has been detected in one of the vehicle’s ignition coils, generally the number 9 coil. This code can also be associated...


Related questions

Q: Sputtering, misfiring, power loss and gain

Hey there: There are usually two different mechanical problems that cause the symptoms you're describing with your Pontiac Firebird. The first and most common is a problem with the ignition coil, (especially in mid-90's GM V-6 engines) or due to...

Q: How can I tell if it's my timing chain or something else?

Hi, thanks for writing in. Unfortunately, I will need a bit more information before confirming if the issue lies in your timing chain or not. Your car can certainly run and start with a timing issue, however it is not...

Q: Unable to go past 70-80 Km when going up a hill. Code P0174 with flashing engine light

Hello. A flashing Check Engine Light is an indicator that the computer has detected an issue that may potentially cause harm to the vehicle's emission system components. The code P0174 indicates a lean condition on bank 2 of the engine....