P21FF

Symptoms

• Increased fuel consumption
• Reduced engine power
• Black smoke from the exhaust pipe
• Unstable engine operation at high speeds
• Gasoline smell from exhaust

Causes

• Oxygen sensor malfunction (bank 2)
• Problems with fuel injectors (seizing, leaks)
• Malfunction of the mass air flow sensor (MAF)
• Increased pressure in the fuel system
• Air filter dirty or damaged

How to Fix

1. Check and, if necessary, replace the oxygen sensor of bank 2
2. Diagnose and clean or replace fuel injectors
3. Check the operation of the mass air flow sensor and replace if necessary
4. Check fuel system pressure and pressure regulator
5. Replace the air filter

Related codes

Error P21FF by Vehicle Brand