C0075 Alvis Tc108 is described as Oxygen Sensor Circuit No Activity Detected (Bank 1, Sensor 1). This means there's a problem in the front oxygen sensor on Bank 1, as the O2 sensor is inactive. The PCM then uses this data to provide the right strategies for the fuel delivery and ignition timing of the engine.
Possible Causes :
Look at the plug wires to make sure they are not burnt or laying on the exhaust. 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. It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem.
Diagnostic trouble code C0075 Alvis Tc108 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 C0075 Alvis Tc108.
Fortunately, C0075 Alvis Tc108 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.