I?m trying to tune a 1999 silverado with a 4.8. Texas speed 223/226 at 50, 600lift. I have maf failed. Gets code p0103 on start up. The main ve table seems to have no effect on the truck. I can change secondary ve and change the afr. The truck was also getting a p0121 tps vs map which I assume is from the big cam. I disabled the 121 code. I need some advice to get it to run on the primary ve table. I am trying to learn and know just enough to get myself into trouble.