LS4 swap, speedometer reads double (fixed gas gauge problem)
2008 LS4 in a 2002 Pontiac Montana.
Scanner shows ECM speed output same as speedo, exactly double. So its not an instrument error.
Not too much differemt bt 2002 and 2008. I wouldnt have expected this issue, of all things that could have gone wrong!
Everthing else is flawless. I turned off DoD for now til the speedo issue is fixed bc it was freaking out.
Any help is greatly appreciated. I was going to post screenshot of speedo but can't on mobile.