So i got my truck smogged in the most strict state there is.It passed emmisions but not visual inspection. My main issues they said were a couple broken vacuum lines , check engine light coming on and off and my timing was set at 9deg tdc. They said it has to be 4. My question how to I change it via the computer or at the distributor. Its an 87 sub 3/4 ton 454fi. How do i do this?
