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 Long Does a Fuel Filler Neck Last?
Getting gas from the pump to your gas tank is the only way to keep a car going. The fuel filler neck is a metal tube that is welded to the...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...


Related questions

Q: What parts will I need for a timing chain replacement and how many of each. Is my engine interference or non interference?

Hello - your engine does use a timing chain, and that engine is not an interference (valve-to-piston) engine. However, having said that - if the chain breaks, especially at anything above an idle, the broken chain can jam the crankshaft...

Q: Check engine light comes on and engine stalls but starts right back up. Upon restart the check engine light is off with no problems.

Hi there. It seems that there could be a loose wire or loose ground to the transmission sensors. First you will need to get a scanner and scan for any codes that are pending or stored in the ECM (computer)....

Q: I have a p0174 code that was reviewed on a scanner.

Hi there. The code P0132 in on for an issue with the upstream oxygen sensor. There could be a broken wire, frayed wire touching something metal, or the sensor could have failed. The code P0174 is on for the Mass...