Skip the auto shop - Our mechanics make house calls

P2189 OBD-II Trouble Code: Sys Too Lean at Idle Bank 2

Check Engine Light

P2189 trouble code definition

The most environmentally friendly and power efficient air-fuel ratio for gasoline engines that we modernly know is 14.7:1. The engine control module (ECM) is programmed to adjust things like fuel delivery and ignition timing if needed to keep the air-fuel ratio at or near the 14.7:1 ratio. Trouble code P2189 indicates that the ECM has determined that there is too much air and too little fuel present in the air-fuel ratio during engine idle.

What the P2189 code means

This code indicates that during the last two drive cycles, the ECM has observed a lean air-fuel ratio condition on bank 2 of the engine. The manufacture designed the ECM with the ability to adjust the air-fuel ratio by changing the ignition timing and fuel injection pulse width to help achieve 14.7:1. The ECM can only adjust the air-fuel ratio to a certain extent. If the margin of adjustment is too wide for the ECM to correct the lean condition, then a code P2189 will set.

What causes the P2189 code?

  • Faulty EVAP system purge valve
  • Vacuum leak
  • Faulty crankcase ventilation valve
  • Leaking crankcase ventilation valve grommet
  • Leaking intake manifold gaskets
  • Loose intake manifold
  • Faulty bank 2 oxygen sensor
  • Fuel pressure low due to weak fuel pump
  • Restricted fuel supply such as pinched fuel line or clogged fuel filter
  • Air intake leak
  • Loose oil cap
  • Faulty gas cap seal
  • Leaks in the exhaust system
  • Mechanical issue in one or more of the bank 2 fuel injectors
  • Faulty manifold absolute pressure sensor
  • Faulty fuel pressure regulator

What are the symptoms of the P2189 code?

  • Check Engine Light illumination
  • Misfire at idle
  • Engine hesitation
  • Engine hard to start, especially when warm
  • Whistling noises coming from the engine area

How does a mechanic diagnose the P2189 code?

  • Performing a fuel pressure test
  • Performing a fuel injector flow test
  • Inspecting the EVAP system for leaks
  • Inspecting the intake manifold for leaks
  • Inspecting the air intake and vacuum lines for leaks
  • Inspecting the crankcase ventilation grommet for leaks
  • Inspecting the rubber seal of the gas cap
  • Performing an inspection of the exhaust system
  • Using a scan tool to view the long and short-term fuel ratio
  • Using a scan tool to view the oxygen sensor live data

Common mistakes when diagnosing the P2189 code

Often times, a mechanic may not check the vacuum lines and EVAP system of the vehicle. The EVAP system and vacuum lines are among one of the most likely things to cause a lean condition.

How serious is the P2189 code?

It is fairly serious because an improper air-fuel ratio will generate excessive emissions, which will cause harm to the environment.

What repairs can fix the P2189 code?

Additional comments for consideration regarding the P2189 code

As there are many components which can cause this code, it is recommended to have an experienced technician point out the faulted component through proper testing and inspection to save time and money.

Need help with a P2187 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

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...


Related questions

Q: I have the check engine light on and checked for DTC's it says ECM set and CEM set

Hi there, thanks for writing in about your Volvo. There should be specific alpha numeric "codes" displayed on the Code Reader. Do you see/have those "codes"? These will help pinpoint any faults and assess the issue. I would recommend having...

Q: Why would I still have a check engine light after my camshaft and crankshaft sensors were replaced 2008 Kia Sedona

If you are continuing to get the same codes after these sensors were replaced then you more than likely have a worn out timing belt. When the belt is worn then the sensors will not read correctly. If you want...

Q: I had the catalyst converter replaced last year. Now the Check Engine Light is on again for O2 sensor. What do I do?

You may want to have a professional inspect the catalytic converter. When the Check Engine Light comes on for this, it does not necessarily mean that the catalytic converter has failed. This may be related to many other things as...