[BonzoHansen]

I still see nothing about needing a 4th gen cluster for evap to work. what I just read is you must keep the fuel sender signal to the ecm. ecm feeds the dash, not the other way around. all those links talk about how to get the gauge to work, and bypassing the ecm bangs up evap codes. of course, that is what the book says.

Adam, you probably have all-data or something, maybe I missed something, read the manuals and dtc charts. I saw zero reference to the gauge cluster in the evap or fuel pressure sensor DTCs. but a precondition for many related codes is 15%-85% fuel level. sender wires go to ecm, that is what matters to the ecm.

I still point to the new GM e-rod crate setup. it comes with evap. how does it work? Mr GMI ought to be able to get some tech help from gm I'd hope, someone at GMI must have a GM contact.

that programmable fuel gauge is trick.