Recently installed Xfi and got everything working well minus the VSS input. It's very erratic reading 200mph then 110-then 50 then 125---speed cable is quilte and smooth all well correct with stock ECM and PL/sd2 setup-I have ran a wire from the xft a5 to the factory harness bypassing the caspers box and it's the same. I have picked a few people's brains at the show and my next step is to check the voltage input at a5 of the xfi box. Any ideas?