why does my civic through puffs of smoke

[VTEC BOYS]

i just had a decat exhaust sytem fitted in my civic 1.8 vtec dohc, i have noticed that when i rev the car and let go of the paddle blackish n blueish puffs ofsmoke is thrown out ut not when i push the paddle so i dont know wats the problem and it does not drink oil as well

[EvoBarry]

Sounds like bore wash, just excess fuel washing the bores of oil and burning it off... Honda engines tend to run a touch rich from the factory I believe.

[eybic]

Blue is oil, black is fuel. Hopefully it is more black than blue?

[Civic14]

Its usually all good, as that other guy wrote if its blue its bad. Turbo'd cars usually puff smoke on boost where as n/a cars tend to puff it a high revs with the excessive fuel in the cylinders. Sometimes cars need a thrashing if they have been drivin slowly for a while, This will get rid of the carbon. Its a mechanics trick,

[RobCrezz]

My old prelude used to always make a little blue smoke when using vtec, didnt ever cause a problem though, just keep the oil topped up.