Q: What would cause my vehicle to misfire in all 4 cylinders and throw two codes for air/fuel ratio heater circuit malfunctions?

One of the codes (P0115) refers to the coolant temperature switch circuit. If the circuit has a fault, you may be getting a false indication of the actual, and perhaps too high, engine operating temperature. The cooling system is pressurized in operation. Consequently, if there are any leaks at all the system will malfunction, there will be internal boiling, creation of air pockets, and thence possible false reporting of an actual overheating condition. The cooling system should be repaired coincident to a no start diagnostic. As far as the other codes, the two relating to the O2 sensor heater circuit refer to mundane heater failures which are easy to test for. Misfiring (P0300, etc.) is typically due to faulty spark plugs, too lean operation, vacuum leaks and so forth. Your best entree to getting all of this promptly resolved is to request ano start diagnostic。经过检查后，机械师将使汽车运行，并建议您进行所有必要的维修，以将汽车恢复到可靠，安全的操作。如果您有其他疑问或疑虑，请随时重新接触万博体育入口因为我们一直在这里为您提供帮助。