I replaced mine then I bought a used engine so I have almost 2 sets (I gave 1 away..) and no I think I'll keep them. Replacing them was a waste of cash I think now.. if it aint broke. Techron comes 2 different ways. When you want to clean the fuel system get the concentrated! they have both at walmart and probably parts stores. The non concentrated is slightly more then you get filling your tank at chevron.

 

Well, I can tell a pretty big difference.
Not only were my injectors in bad shape, but the injector the engine rebuilders installed in cylinder 8 was a silver body with three fuel nozzles. The others were yellow body with 4 nozzles.
Haven't refilled yet, but I am used to seeing around 70 miles on the trip odometer when I hit 3/4 of a tank. I hit 101.3 miles last night and was at the same point.
The first thing I thought about was a lot of people on various forums stating they get the same gas mileage whether running it hard or taking it easy, or towing. That to me would throw up a huge red flag, the truck would have to be metering the same amount of gas regardless. My truck was doing the same, and looking at the fuel trims keyed me into the MAF and then the injectors being the problem.

There have been several good threads on the bobistheoilguy.com forums concerning techron.
It is good for preventative maintenance but doesn't do much if the fuel system is already in bad shape. Also, the non-concentrate is quite a bit stronger than normal chevron gas, which has very little additive. But I agree, if you're gonna use it, get the concentrate.

 

If you use top tier fuel You really dont need to worry about the fuel system or additives. There are guys who are running original injectors that are 17-18 years old with 5-4 hundred thousand miles on them.

 

Except, I don't know what kind of fuel has been ran in it the last 160,000 miles. I bought it used.