First let's calm down here.... :lol:
If you flip out and start throwing random parts at your car to "try to pass" you might end up causing a problem that will cause it to fail.
Ranger is right, don't worry about snake oil or magic bullets. Head to an inspection station and get the car smogged.
Now let us back up a bit. Your "PPM" is not a thing. That means parts per million and all the gases are pretty much measured in ppm. You have HC (hydro-carbons) CO (carbon monoxide) and NOx (oxides of nitrogen) that will be measured. Which one was close?
On a 4.1 you are usually going to see high NOx.
The issue there is that NOx forms at higher combustion temps (hot engine) and the EGR valve is in charge of handling it. The EGR passages have a tendency to plug on those engines.
Look around and see if you can find procedures on how to clean them. If you can't find anything I might be able to post up something.
From there just go get tested and post up the readings if you fail. I can usually tell from the readings what you need to start with.
If you don't have misfires and the car is running fine, leave it alone.
Replace parts AFTER you fail based on the readings that you get.
Those snake oil salesmen are counting on you being nervous about failing but it really isn't that complicated.
If you have parts that need replaced, magic in a can isn't going to get you through.
Most of the "tricks" out there will actually do more harm to your car than they will help it to pass.
I am an emissions inspector in my state and I am actually in the middle of my 3 year mandatory renewal class time to keep my license.
I'd be happy to help when I have time but I have to have something to go on besides commercially induced fear.
