Are we who use HHO gas injected into our engines BREAKING THE LAW. Here is what the  (EPA) U.S. Environmental Protection Agency has to say about HHO GAS and Hydrogen on Demand.  40 CFR Part 85 Sub part F requires certification of aftermarket fuel conversions to avoid violating the anti-tampering provisions in Section 203(a) of the Clean Air Act. EPA considers supplemental fuel systems such as an on-demand supply of hydrogen to be a type of fuel switching. You will likely find many types of fuel conversion kits on the web, including hydrogen on demand kits. Most all are illegal and our office generally refers these to our Enforcement Office when they are brought to our intention.   People this is wrong. I for one have proof with two separate vehicles we tested and they absolutely did get much cleaner results at the smog test. Why would the EPA not allow Hydrogen on Demand ADDED if it proofs to clean up the emissions.  The EPA, and others who have never installed a hydrogen on demand system are misguided. These retrofit hho generators and Hydrogen on Demand  systems are merely a supplement, they do not replace gasoline and are not intended to, it's an additive, not a switching of fuel type like the EPA says. The people who use this HHO technology must stand up. I am compiling a massive list of proven results that adding HHO GAS to your gas or diesel vehicle does reduce harmful emissions, if you can offer any proof please contact me.  If you want more information on this subject or Free plans to build your own HHO generator go HERE.