I used a second bottle of that "ultra fuel treament" and responsiveness of the engine has markedly improved.
I said earlier that I was to run a third bottle right before I do my next oil change, but I decided not to. The car has improved so much, I passed the test after the first bottle and I decided to use a second treatment to see it there would be any improvement.
I do not want to push my luck. If I fail the test in two years, then I'll give it another bottle.
BTW, here in Ontario the test is valid for a period of 12 months. So what I do is take the test 11 months and 3 weeks earlier. Instead of taking the test right before my birthday, I take it right after my birthday, but almost a year ahead of time. This gives me almost a year to fix anything that needs to be fix. I suggest you do the same.