I don't think the PCM will make adjustments to the timming when you add HHO to the mix. How will it know when it's there, Higher Oxygen readings at the O2 sensors, that will just richen up the gas mixture. I havent hooked up my system yet but I think the timming should be retarted about 5 to 10 deg. HHO makes a faster and more complete burn. I've seen my GMC sierra reach 53 deg before TDC with gas only, that's way to soon for ignition with HHO.
In my quest to learn about HHO and it's use I have taken another road to tricking the PCM. I'm reading how to change the tables in the computer to avoid popping codes.
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