Hello. So I have this Mazda 3 2.0 diesel and I encounter performance issues. Motor vibrates sometimes while standing still and performance is lacking. Sometimes it goes stronger, sometimes way worse than it should. Also at cold start it shoots bunch of white-blueish smoke. And if I accelerate from 1.5-2k rpm it feels like it loses torque when it reaches 2.5-3k rpm. Check engine light is not on. Any suggestions? I'm thinking injectors?