HC Adsorption Catalyst Efficiency Below Threshold - Bank 2

Common Symptoms

• Check Engine Light illuminated
• Failed emissions test for hydrocarbons
• Mild fuel odor from exhaust
• Reduced catalytic converter efficiency on bank 2
• No significant drivability symptoms

Probable Causes (Ranked by Likelihood)

• Degraded HC adsorption catalyst on bank 2 Very High
• Rich fuel mixture contaminating bank 2 catalyst High
• Exhaust leak on bank 2 before the catalyst Moderate
• Oil consumption fouling the catalyst Moderate

Step-by-Step Diagnostic Procedure

1. Compare bank 1 and bank 2 catalyst efficiency readings

2. Check for rich-running conditions on bank 2 using fuel trim data

3. Inspect exhaust manifold and pipes on bank 2 for leaks

4. Check for oil consumption that could foul the catalyst

5. Evaluate O2 sensor readings upstream and downstream of the bank 2 catalyst

Frequently Asked Questions