B0221 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code.
It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.
Symptoms of a B0221 diagnostic trouble code may include:
Possible spark knock (detonation / pre-ignition)
Poor fuel economy
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Possible Causes :
Fuel with a large percentage of sulfur will clog the DPF quickly
The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Defective ECU strategies or components will prevent proper regeneration
Repair Processes :
Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness.
Look at the plug wires to make sure they are not burnt or laying on the exhaust.
If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs.
Diagnostic trouble code B0221 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.
Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before B0221.
Fortunately, B0221 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.