I'm running a 12587603 OS, the truck cranks, idles and runs great but it is boosted so I did the cos upgrade with 04073003 and followed the instructions exactly and it will not run. The most I get is a brief start then just shuts down like vats would do but it is disabled. Plugs are wet also. Every table is the same including ifr. I'm using this tune because it is dbc, boosted and flex fuel. I'm using the correct van ecm also. Thanks for any help you can give. On a side note I have used cos OS many times before with no trouble.