B0103 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 B0103 diagnostic trouble code may include:
Cherry red hot catalytic converter
Possible spark knock (detonation / pre-ignition)
Reduction in engine performance, especially at low RPM levels
Possible Causes :
A faulty oxygen sensor. This will set a code in itself, however, a faulty oxygen sensor does not automatically condemn the sensor. The code just means that the sensor signal was not within specifications. An air leak or any of the above will cause an erroneous signal. There is a multitude of O2 codes relating to O2 performance which gives a clue to the problematic area.
Some aftermarket accessories and performance modifications
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Repair Processes :
With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.
Now, clear the codes and test-drive the vehicle to see if the code is reset.
Diagnostic trouble code B0103 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 B0103.
Fortunately, B0103 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.