[speedracer07]

My 06 a puff of white/blueish smoke for one second at startup only and that not all the time, any suggestions why this happens, one morning a while back I started the car and sounded rough, I immediately shut it off and restarted it to see the first time a cloud of smoke, I plugged the diagnostic tool and found two codes ( my bad I didn't write them down) I cleared the codes only to find out couple of months later the car didn't register on the DMV Smog machine...no pass, was told to drive it ,a couple hundred miles it passed with no problem.
Question is what could have caused the rough start and why now a cloud of smoke at startup?
Any suggestions will be greatly appreciated!

Thanks!