Definitely wont help secondary air, might help slightly if you have no blockage. However it does it, it certainly cleans carbon out. The 4 that I used the product on were our oldest worst vehicles and one would not pass the etest anymore. That one passes and although we have not fixed the others they run well enough to keep in the fleet. We have not put it in a newer vehicles, but we will. All of the vehicles I ran this stuff thru had symptoms of dirty valves which was putting the nail in their coffins. The dirty valve symptom disappeared from all.
These are ford vans and chev pickups with 350k+ kms on them. It was an improvement for all and what I am hoping is that a once a year treatment will prevent the build up that caused the 350k vehicles to be candidate for the wrecking yard.
What maintenance can you do for $170 in cleaning the inside. Not much! My cost will be much less. This is not a wonder drug, but appears to clean enough that the vehicle does not have a heart attack. I do know that it appears to clean crud out of the cat at minimum, which probably makes the post cat a bit happier. On our cars a treatment is the same price as 2 post cat O2 without the install.