b16 swap recently started throwing code 21

[JuS JAi Bee]

so as the title states b16 swapped eg everything has been good for about a year now... last week sometime it started throwing code 21... same say i started to get a weird white smoke (on start up and around 4500 rpms it gets heavier) from the exhaust please any help much appreciated... thanks in advanced...

 

[AHHVTEC]

check your oil make sure you have enough in there, and white smoke is not good that means coolant is burning

 

[t3t4delsol]

is the smoke white or is it white with a blue tint?

 

[JuS JAi Bee]

oil level is perfect just changed it... umm... its dark right now so i cant really tell about the tint to the smoke.... but something i did notice earlier on today... i removed the header... just to see where the smoke was coming from... and its only the number 1 cylinder.... and as substance similar to oil is leaking thru that same cylinder.... but it doesnt feel like oil... its watery like maybe unburned gas and carbon.... its so weird