Manifold abs pressure

[chevyboy3672]

I got my CTS2 last nite and hooked it up and today it keeps alerting me manifold abs pressure but it doesn't throw a check engine light and the alarm on the edge unit set at 40psi specs on the truck are aem intake bd diesel heater grid delete and intake and piping egr and dpf delete 5" exhaust the tune is unknown my dad go the truck with the egr and dpf delete on it