What are the symptoms of a faulty oil control valve?

[Catalina]

If the oil control valve is faulty, the vehicle may stall during driving and may also experience excessively high oil pressure. When the oil pressure is too high, it can lead to an overly rich air-fuel mixture, black smoke from the exhaust pipe, insufficient power, and may cause low oil pressure or even failure to establish oil pressure, increased fuel consumption, requiring immediate attention. Fuel system pressure inspection method: 1. Pressure relief: Before checking the fuel system pressure, it is necessary to relieve the pressure first. Remove the fuel pump fuse, relay, or fuel pump plug, then start the engine until it stalls on its own. After that, start the engine again and disconnect the negative terminal of the battery. 2. Install the fuel pressure gauge: Connect the fuel pressure gauge in series with the fuel line to inspect the fuel system pressure. When removing the fuel line, place a cloth or cotton pad under the fuel line connection to prevent fuel leakage on the ground. Install the fuel pressure gauge onto the fuel pressure gauge adapter, and finally, for vehicles with a pressure test port, connect the fuel pressure gauge to the test port.