2007 Nissan Murano constantly smoking

[Finjann]

Good afternoon,
I purchased a 2007 Nissan Murano with only 96k miles on it, from the auction.
The previous owner had a sirion and electric box installed (so there's some electrical issue), which is not a big deal.
The biggest problem is the car constantly smoking from the exhaust (I've never seen something like that before).
Initially, when I first ever started the car, it smoked for like 10-20 seconds but then the smoke was gone and only when I revive the engine.
The car then started smoking constantly ( see the video please).
Check engine light is on for MAF sensor.
Is that piston ring or head gasket !!! ??
I sent the video to a friend who told me its possibly clogged Catalytic converter!!!

https://youtu.be/Fp6x36qpsbo




Any info will be much appreciated.
Thanks,
Omar

[VStar650CL]

That smoke is white, so it's either fuel or coolant. Coolant will smell slightly sweet and not particularly unpleasant, fuel will smell acrid and extremely unpleasant (choking, in those quantities). Both can occur on startup and then disappear. Pressurized coolant "cooking" after shutoff will force its way past a bad head gasket and trickle into one or more cylinders, then emerge as a transient cloud on startup. Fuel can have the same effect from gravity drip from a bad injector seal or sticky plunger. If the smell doesn't make the source plain, get a chemical test kit for combustion gasses in the coolant.

[Finjann]

I think its a head gasket, I topped off the coolent today in the morning and its empty now