On the back side of the throttle (passenger side) you will see a vacuum hose that goes down to a gold anodized device, that is the Fuel pressure Regulator.
It is the Clear hose in the Picture at the back of the throttle body Pull it off the nipple of the throttle body. Insert your hose there, then into the Seafoam can. Or you can Spray Carb cleaner in that hole too. You will have to slightly increase the rpm, and have your car half out of your garage as you will be killing tons of Mosquito's throughout your neighborhood.
You will also find out if your exhaust manifold is cracked.. as more smoke will come out the manifold than the tail pipe.
Grounds, Grounds, Grounds Replace them things.
Divorces, Great Coffee, and Electrics, all start with GOOD Grounds. Where are my grounds ?