this is an obd2 trouble code reader, it can help you understand the meaning of code. http://www.chinasinoy.com/service/how-to-understand-trouble-codes-37.html Possible causes of OBD code P0030: Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground - Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection - Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit - Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse - Faulty Engine Control Module (ECM) The Error code is generally activated on detection of the following conditions: The P0030 is set when the ECM detects an open or shorted to ground condition on the heated oxygen sensor heater circuit Possible Solutions: The code means that there is a problem with the heater element circuit of the heated oxygen sensor. Water getting inside the heated oxygen sensor connector can caused the heated oxygen sensor fuse to blow, which is a very common problem for this type codes. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. HO2S Heater Control Circuit Bank 1 Sensor 1 is the generic definition for the P0030; however your vehicle's manufacturer may have a different definition and information for the P0030 code. hope help.