Lexus Rx300 P1150,P0304,P0300,P0306,P0125,P0174

Codes P0300, P0304, P0306 are all misfire codes and so yo need to address/replace your spark plugs and maybe replace your coils as well. A P0174 is a lean mixture code, here is an article that covers an explanation of this code, that I wrote. Many people and shops have used it. https://repairpal.com/OBD-II-Code-P0171-and-P0174 P0125 is a thermostat code, your thermostat needs to be replaced, it is letting the engine run too cool for too long during warm up, and you are using way too much gas as a result. P1150 is a problem with your air fuel sensor in bank 1 sensor 1.