What it means
The engine control module detects a rich air-fuel mixture at idle on bank 2. The code identifies the operating condition; it does not by itself identify the cause.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The engine control module uses oxygen-sensor feedback and fuel trims to assess the mixture on bank 2, the side of the engine opposite bank 1. P2190 is set when the mixture is detected as too rich specifically at idle on bank 2; it does not by itself identify whether excess fuel or incorrect air measurement is responsible.
Common causes
Most likely first.
- Leaking injector at idle on bank 2
- Purge valve stuck open
Symptoms
- Check engine light on
- Increased fuel consumption
- Black smoke from exhaust on acceleration
- Smell of unburned fuel, fouled spark plugs
How to diagnose it
- Check freeze-frame data and compare bank 2 fuel trims at idle with readings at higher engine speed to confirm the rich condition is concentrated at idle.
- Inspect bank 2 spark plugs and exhaust for fuel fouling, soot, or unburned-fuel signs that can help identify the affected side.
- Check for related injector, purge, oxygen-sensor, or fuel-pressure codes and review upstream oxygen-sensor data on bank 2.
- Test bank 2 injectors for leakage after shutdown or at idle using the manufacturer's procedure, since a leaking injector can overfuel that bank.
- Check whether the evaporative-emissions purge valve is stuck open and allowing excess vapor into the intake at idle.
Common fixes
- Repair or replace a purge valve confirmed to be stuck open.
- Clean or replace a leaking bank 2 fuel injector after confirming which injector is leaking.
- Repair wiring or connections affecting bank 2 oxygen-sensor feedback if testing identifies a circuit fault.
- Correct any verified fuel-pressure or air-measurement fault contributing to the rich idle condition.
Can I keep driving?
Limit driving if the exhaust smells strongly of fuel, produces black smoke, or the engine runs poorly; excess fuel can foul plugs and damage the catalytic converter. Arrange diagnosis soon, particularly if the check-engine light flashes.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.