Check engine light came on an losing fuel as tje result

Hello, it's hard to say what's going on with your check engine light, without a proper diagnosis. Certain things that can cause a "check engine light" can cause a loss of fuel economy. But a proper diagnostic test by a qualified technician can help determine what is happening with your Escalade. Here are some techs near you that can help figure out what is going on: http://repairpal.com/cadillac-within-10-miles-of-gulfport-mississippi-39507.