System Too Rich at Idle -- Bank 2
What does P2190 mean?
The P2190 code means the vehicle's onboard diagnostic system has detected: System Too Rich at Idle -- Bank 2. This is a moderate severity code.
Common Symptoms
- Rich exhaust smell from bank 2 side
- Black soot on bank 2 exhaust tip
- Rough idle
- Fouled spark plugs on bank 2 cylinders
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Leaking fuel injector(s) on bank 2 Very High
- Faulty bank 2 oxygen sensor reading false lean High
- Excessive fuel pressure affecting bank 2 delivery Moderate
- EVAP purge valve stuck open introducing fuel vapor Moderate
- MAF sensor overreading causing excess fueling Low
Step-by-Step Diagnostic Procedure
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Check bank 2 fuel trims at idle -- long-term fuel trim below -15% confirms rich at idle
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Compare bank 1 and bank 2 fuel trims -- if only bank 2 is rich, focus on bank 2 components
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Perform fuel injector leak-down test on bank 2 injectors
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Test bank 2 oxygen sensor response with propane enrichment -- sensor should respond quickly
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Check fuel pressure regulator for leaking diaphragm
Frequently Asked Questions
Can I drive with code P2190?
Yes, the vehicle is safe to drive. However, the rich condition on bank 2 will foul spark plugs on those cylinders over time and can damage the bank 2 catalytic converter. Repair within a reasonable timeframe.
How can I tell which injector is leaking?
Pull the spark plugs on bank 2 cylinders and compare their appearance. The cylinder with the leaking injector will have a noticeably blacker, more fuel-fouled spark plug compared to the others. A professional fuel injector flow and leak test provides definitive results.
Could a bad O2 sensor cause a rich condition?
Yes. If the bank 2 oxygen sensor is sluggish or reading falsely lean, the PCM will add extra fuel to compensate, creating a rich condition. Test the O2 sensor response time -- it should switch between rich and lean at least 6-8 times per 10 seconds.