@mikestang63 @Killa @stykthyn about Miss After Sitting I read the ingredients on Seafoam - petroleum distillates. I also read the ingredients on Techron - Light petroleum distillates. Neither is very specific, but neither sounds all that harmful. Petroleum distillates may not be stronger than the gas, or it may be lighter fluid. B-12 Chemtool ingredients - Toluene, Methanol, Acetone, 2-Butoxyethanol, Methyl Ethyl Keytone (MEK), Isopropanol. So that is at least four GOOD solvents and lots of stuff you do NOT want to have prolonged exposure to your skin. I am sure you can run Techron Concentrate in each tank without causing a problem. But if you want something cleaned out, there is no contest. At the stealership I used to work at, the mechanics told customers if the B-12 Chemtool does not do it, it was time to get the injectors manually flushed and cleaned.