mazda_matteo
+1y
i dont think it would be the O2 sensor cause if it was getting excess fuel the smoke would be black in color. And i had a 89 that smoked pretty bad in the morning for a couple of mins but the smoke was definitely a blue color and the engine had lots of blow-by so it was oil getting past the rings until they warmed up enough and expanded. Does it go away when warmed up? although your smoke looks pretty white which leaves me to believe its coolant getting into the chamber, possibly a bad head, cracked or warped?