Check engine light on 2002 Chevrolet Astro

This van is not getting enough air in the fuel mix. When the check engine light comes on the fuel efficiency goes in half and it uses a lot of oil. I replaced the air flow device and some cables.. It did n't help. The light comes on after the engine is warm and after I fill up with gas. When the light is on the van will occasionally run rough

Asked by for the 2002 Chevrolet Astro
What OBD codes are you getting? It's possible you have an internal fuel leak.