OBD-II Code · Fuel & Air
P2189
System Too Lean at Idle (Bank 2)
Severity
medium
Worth booking. It costs fuel, emissions or comfort until it is fixed.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$50–$400
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Bank 2 lean at idle.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Rough idle
- Check engine light
Likely causes
- Vacuum leak bank 2Most common
- PCV
Read the full diagnostic procedureP2189 is the bank 2 mirror of P2188 — the fuel system on bank 2 runs lean AT IDLE specifically, with STFT + LTFT pinned above +15% at warm idle and t…
P2189 is the bank 2 mirror of P2188 — the fuel system on bank 2 runs lean AT IDLE specifically, with STFT + LTFT pinned above +15% at warm idle and trims returning to ±5% the moment the throttle cracks open.
Because the code is bank-specific and idle-only, the diagnostic narrows fast
anything that affects both banks globally (low fuel pressure, dirty MAF, weak pump) typically throws P2188 AND P2189 together, so a solo P2189 points at a vacuum leak or intake fault mechanically isolated to the bank 2 side. Cheapest-first: smoke-test the bank 2 intake runners, the bank 2 PCV breather path (many V-engines route the PCV to one bank and a fresh-air breather to the other), the bank 2 intake-manifold gasket, and any rubber elbows on that bank. Check for exhaust leaks ahead of the bank 2 upstream O2 sensor — a crack at the manifold flange pulls atmospheric oxygen into the sensor's reading and fakes a lean condition. Compare bank 1 vs. bank 2 STFT at idle: bank 1 at +3% with bank 2 at +22% is the photograph of a bank-2-only mechanical leak. The at-idle code is the giveaway — don't condemn the O2 sensor; the sensor is correctly reporting that bank 2 sees more air than fuel at idle. Find the bank-2 unmetered air source.
Vehicle-specific patterns2007-2014 Ford F-150 / Expedition / Navigator with the 5.4L 3-valve Triton V8 throws P2189 alone from a cracked composite intake manifold on the pass…
- 2007-2014Ford F-150 / Expedition / Navigator with the 5.4L 3-valve Triton V8 throws P2189 alone from a cracked composite intake manifold on the passenger (bank 2) side near the EGR port — Ford issued multiple TSBs and the upgraded composite-plus-aluminum manifold is the durable fix ($350-$500 part, $700-$1,100 installed).
- 2005-2010Chrysler 300 / Charger / Magnum 3.5L V6 throws P2189 from cracked rear-bank intake-manifold plenum gaskets.
- 2008-2014BMW N63 twin-turbo V8 (550i, 750i, X5/X6 5.0i) throws P2189 from bank-2 intake-side oil-separator failure and from cracked intake boots between the turbos and the intake manifold.
- 2006-2012GM 5.3L Vortec V8 (Silverado, Tahoe, Suburban) throws P2189 from a torn bank-2-side intake gasket and from a failing PCV fixed-orifice on the valley cover.
Estimated repair$90 to $1,100.
Look up another code
P2189 — frequently asked
What does a P2189 code mean?
Bank 2 lean at idle.
What causes a P2189 code?
Common causes: Vacuum leak bank 2; PCV.
What are the symptoms of a P2189 code?
Typical symptoms: Rough idle; Check engine light.
Is it safe to drive with a P2189 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $50-$400.
How do I diagnose a P2189 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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