Q: A Geely Global Hawk Freeland, the engine fault light is on, fault code P0304, engine 4 cylinder misfire. Spark plugs, ignition coils have been replaced, and the fuel injectors have been cleaned, but the fault still exists. How should it be repaired?
A: This type of fault is quite common. First, check the freeze frame data of the 4-cylinder misfire, check the misfire value and the status at that time. If it is determined that there is no problem, check whether the cylinder pressure is too low. Low pressure will cause the engine to work unstably, and will also increase the misfire data, causing an alarm, but it does not rule out that the 4-cylinder valve is burned or there is a lot of carbon deposits. I have handled vehicles with faulty fuel rails and found that a large amount of impurities were blocked in the fuel rails. Please do not ignore this.