I've heard that tc-w3 may reduce some compounds in regards to emissions but I haven't seen it myself so I cannot say for sure.
Would acetone/toluene/xylene improve emissions? They reduce the surface tension of fuel which can help it burn more completely.
Believe it or not Lucas upper cylinder lube may also help. It contains polyisobutylene which is known to improve fuel economy buy helping fuel more completely.
Unless you are due for an oil change there's no point in changing it just for the emissions test.
Here's what I would do. Wait til the fuel tanks hits 3/8-1/2 tanks or so. Then add a fuel system cleaner high in pea such as "guaranteed to pass",redline,techron or whichever has the highest pea content or what's easy to get.
So add them to the gas. Now make a point of driving the car at high rpm and lots of pedal for the rest of the tank. The cleaner will do its thing while you are operating really hot with lots of cylinder pressure which all on its own will break loose rings if they are coked up and the increase in air velocity will accelerate the cleaning process. This will also heat the cat up hot and hopefully the heat and increase in velocity,as well as the pea in the fuel which from what I understand loosens and removes deposits by attaching themselves and encapsulatingit,insulating it which prevents re-deposition when expelled. This same process,and the extra heat as well as the air velocity being so much greater it may,for the short term operate until everything gets caked on again.
People don't realize how important it is to drive an engine hard sometimes. It heats up the exhaust yway more and the increase in air velocity acts like a tornado whipping everything inside the intake up cleaning the maf or AIT which helps keep sensors clean,heats the oil up and increases pressure and velocity which helps contaminants dissolve and disperse better as well as moving any larger deposits where less oil is able to arrive.
No need to drive like a retard or anything just go on a highway and drive in a lower gear. 4000 rpm is a good target with some varying pedal,going full throttle but not just mashing the pedal,gradually get yourself there. It's the jack rabbit mashing of the pedals that wreck the mechanical links,so as long as your increase torque by pedalling in lightly it's not really that hard on the drivetrain.
A friend of mine who has an automotive recycling facility once told me 1 quart of acetone in half a tank of fuel in his LS powered retrieval units made them pass their emmisions. He's in Alberta somewhere they have to get sniffed.
Before driving the additized fuel I suggest unhooking the battery and clearing the ecu.
That erases the learned values starting you off at 0 again and clearing any check engine lights.
After the Italian tune up erase the ecu again. Because the sensors will be cleaner they will be more accurate which will affect the exhaust gasses.
But this is just me.
It would be nice to have solid proof that some additive,and an Italian tune up really does make a car pass.
We have a test mule here guys. A real world test. Real data from someone with no skin in the game.
Please keep us informed