Cold start,smokey exhaust, and cold air only
 

Help,
Our beloved Bonny is ill.
about a month ago she began starting hard when cold.Changed Fuel Filter and Fuel injector cleaner cleared this up. For about 1-2 weeks only. I then gave it a routine oil change, I started getting a service engine light. and heavy white smoke out the exhaust pipes. I took it to my brother who has a code reader, and was getting misfire on cyl 6 code. I took it in for a spark plug change they read code as random cyl misfires.I had new plugs put in. Error codes went away. Added some more injector cleaner. She still is hard to start cold and I get hvy smoke out the exhaust, It's definetly mostly white but might be slightly blueish. I really can't tell no funny smell though. Last night my wife gave me an earful because it now only blows cold air out the vents (Auto Climate control), and it's cold here currently. I must add that when I changed the oil I'm afraid that I might have put just a tad bit too much oil in, and figured it was all right because it came just to the top of the hash mark on the dip stick, but was too lazy to jack the car back up and drain a little off.
She is still strong but these conditions are concerning me greatly
I have a 98 SE. 40,000 miles (mostly city)
I would appreciate any help or suggestions.