P2190: System Too Rich at Idle Bank 2
The P2190 code indicates that the engine control module (ECM) has detected an excessively rich air-fuel mixture (too much fuel or not enough air) on Bank 2 (the side of the engine opposite cylinder #1) while the engine is idling. This condition can be caused by a variety of issues including faulty oxygen sensors, fuel injectors leaking, a stuck fuel pressure regulator, or a vacuum leak. The ECM monitors the oxygen sensor readings and fuel trim adjustments; when the long-term fuel trim is excessively negative (indicating the ECM is reducing fuel to compensate for a rich condition), it sets this code.
01. Most Common Causes
- Faulty oxygen sensor (Bank 2, Sensor 1)
- Leaking fuel injector on Bank 2
- Stuck fuel pressure regulator
- Vacuum leak on Bank 2
- Faulty mass airflow (MAF) sensor
- Engine coolant temperature sensor malfunction
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or engine misfire
- Poor fuel economy
- Strong smell of fuel from exhaust
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data. Check for other codes like P0172 or P2191.
Step 2: Inspect for vacuum leaks on Bank 2 using a smoke machine or propane enrichment.
Step 3: Monitor oxygen sensor voltage and fuel trim data with a scan tool. Compare Bank 1 and Bank 2 readings.
Step 4: Test fuel pressure and check for leaking injectors (e.g., using a fuel pressure gauge and leak-down test).
Step 5: Inspect the MAF sensor and clean or replace if necessary. Check engine coolant temperature sensor readings.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code as it can cause catalytic converter damage, reduced fuel economy, and potential engine damage. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost varies depending on the cause. A simple oxygen sensor replacement can cost $50-$150, while a fuel injector or fuel pressure regulator repair may range from $200-$600. Diagnostic fees are typically $100-$150.