White smoke from the tail pipe is normally a sign of burning coolant. Coolant might leak into the cylinder only after the engine is stopped and still hot.
If you didn't feel the misfire it is probably very intermittent. A poor connection between the terminals in a connector would be more common than a bad injector but to be sure you can switch the number 3 injector with a different one to see if the misfire moves to the other cylinder. If it does, replace that injector. If the misfire is still on cylinder 3, check the wiring.
Friday, August 10th, 2012 AT 11:49 PM