Replacing the leaking exhaust pipe should solve your problem. I have a perplexing question about ignition and tailpipe smoke. About half of the time, the motor starts normally after a 2 second or so turnover. When it starts normally, there is no smoke. What you are experiencing with your car is normal.
Gasoline is made up of hydrocarbons.
I can't pass emissions. Limits are HC 220, CO 1.20. I read HC 318, CO 5.63. Timing is ok. O sensor 1 yr ago.