If you have blue gray smoke coming out your tail pipe then you blew your head gasket and you need to stop driving the car. My honda does what your saying minus VTEC cause I have a D15B and from what i can tell and what was explained to me its burning a little water from somewhere or there is the possibility that you could be running to lean or to rich. I am no expert thats just what I have come up with for mine. When was the last time you had a cat done? Is it fouled by any chance? Not sure if that would cause it but i am sure it doesn't help.