P2189: System Too Lean at Idle Bank 2
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - rough idle is likely until repaired.
Symptoms
- Unstable idle
- Stalling when coming to a stop
- Idle smooth once the engine is loaded
Likely causes, most common first
- Vacuum leak on bank 2
- Cracked intake runner or gasket on that bank
- PCV or breather hose split
- Injector delivering poorly on that bank
Read P2189 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P2189 is lean at idle on bank 2. Because the two banks share the throttle body, the brake booster and the main intake plenum, a leak in any of those shared parts normally sets the bank 1 code as well.
So the useful question is whether P2187 appeared alongside it. One bank alone points at something on that side - a cracked runner, one bad gasket, one leaking injector. Both banks together points at a shared leak, and the brake booster hose and the throttle body gasket are the two most common shared culprits.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Frequently asked questions
Can I drive with P2189?
Yes - rough idle is likely until repaired.
How much does it cost to fix P2189?
Typical US repair costs range from $60 for the simplest fix (vacuum leak repair) to $700 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P2189. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.