Another product that works pretty well is the P.I. from Amsoil

 

Hi everyone, I was a Tech at a GM dealership and a tech at Mitsubishi,Not to mention
I owned at one time 2 auto repair shops.
when you run a cleaner thru the intake it is to clean the combustion chamber!
It can be accomplished by feeding the chemical thru a central vac line that will feed all the cylinders. Ussually you slowly feed the chemical in thru a IV bottle with a regulating valve So you dont hydrolock your engine once the right dosage has been run thru your
engine you shut it off and let it sit.
about 15 minutes later or so start it up and rev engine slightly 1500-1800 rpms
and get ready to fog out the area as it will produce alot of fumes-smoke once it clears up
you should replace the spark plugs, some cars you have to relearn the idle by driving the car over 30 mph others you have to do this with a scan tool.
the best product I have found was thru GM they had a three part kit one for the tank,
one for the combustion chamber and upper intake, and a cleaner for the throttle body.
I worked on a old buick that had a ruff idle I did the normal diagnostics and found that the buick had bad motor mounts and needed a tune up. I found the bad mount by power braking the car, also the vibration went away when the engine was jacked up slightly
so after the mounts and a tune up the car still had a slight mis to it. so I put in the old plugs and ran the upper combustion cleaner thru the engine and I was shoked how smooth this guys car was even with the old worn out plugs.

 

The Techron fuel system conditioner also has additives to help your fuel tank sending unit "card" clean. It removes deposits (mostly a sulphur like deposit) and coats the resistor card to prevent future problems. I use it in all our vehicles...the HHR SS, my wife's Avalanche and both of our old school hot rods. As a former GM Service Manager I know how many fuel gauge problems we had in the past, this stuff works well.

No, I'm not endorsing the stuff, just relating my 2 cents worth...it works for me.

 

You can do the same thing with seafoam and a can of throttle body cleaner. Valvoline has a 3 part cleaner aswell available at their instant oil change places. I personally ran a half a can of seafoam through the intake on my SS, been weary of running it through the tank on my GDI engine.

 

I believe that Techron is the supplier for the GM cleaner. The bottles look the same and it looks the same. It is the only thing that I use. I don't think that injector clogging is as big of an issue as in the past. It really makes a difference in our 86 fiero 3.1 v6 and our old turbo grand prix. It seems that the new style of injector is less prone to clogging as well as the quality of the fuel is better especially if you use a name brand fuel.