Hi. I'm from manila philippines. I have a nissan cube 2003 model. And i have problems with my idling. Whenever I'm in traffic and in drive, the whole engine is shaking and my idling goes down. Then sometimes the check engine goes on. I already changed all my engine supports, spark plugs, coils and computer box. But still the problem is there. Would you know what could be the problem? Any help will do. Thank you.