2002 Saab 9-5, 2.3t smokes when leaving the accelerator

if the smoke is after you have been idling at lights for a few minutes , then it is valve stem seals gone hard or worn
if you are driving and accelerate hard as in passing then it will be worn big end bearings over loading the oil rings
turbos with oil seal problems will smoke all the time and if it seems to have no power , that could be from from leaking intercooler hoses, cracked intercooler or intercooler pipes or from faulty dump valve control actuator
check the viscosity of the oil in use as it may not be correct for the operating conditions or mileage of the engine.

HAVE YOU NOTICED COOLANT LOSS,RECENTLY?KEEP THE COOLANT LEVELS FULL,CHECK TO SEE FOR ANY LOSS AT ALL! OIL SMOKE IS MORE BLUE THAN WHITE,BUT FUEL CAN HAVE A LIGHT BLUE SMOKE.Antifreez more whitesh with a similar smell of antifreeze.

You have a blown head gasket.

What colour smoke is it..... if its Black then the pump is over fueling so both pump and injecters need doing.
But if the smoke is BLUE then you have engine problem like Rings or Valve guides etc
so lets hope you have BLACK
Have a good day

The smoke you could be seeing may be steam, your heater inside the vehicle may have a leak and causing steam to rise out of the vents, if you are smelling the steam this is what I suspect.
Engine vibration could be a number of things, check the engine mounts to start, one of them is probably broken.

you put 2 many oil in the engine

if its white smoke you have a blown head gasket.

is car consuming any antefreeze? does the temp fluctuate? on worst case, you could be looking at poss. headgasket problem white smoke is usually antifreeze. black smoke is fuel, and gray smoke is oil

One way to check for a blown head gasket, is to simply smell the coolant reservoir. Pop the cap, and see if it smells like raw gas. Every headgasket, I've diagnosed has had this smell, even if the oil is not contaminated. Another way is to hook up a coolant pressure tester, and run the vehicle for 15-20 mins or so. If the head gasket is blown, the pressure will exceed 15 psi. sometimes as high as 25 psi. If there is oil in the coolant overflow tank, the head is cracked, about 90% of the time.
I'm working on a 03 Saab 95 2.3l t. This vehicle smokes on initial start up, then the smoke disapates, and the vehicle is fine. Another mechanic diagnosed it as bad valve seals. I disconnected the pcv system, and the vehicle no longer smokes. If the valve seals have gone bad, the vehicle will smoke on acceleration. Also if the turbo seals are leaking it will smoke more heavily on acceleration.

White smoke from exhaust = water into the cylinders, when this happens it usually means head gasket gone or starting to go.
Check the water level, and take the car to the garage for a check up , if it is the head gasket, as I think, you risk to blow the engine at any time.