Hello Everyone. I am new to this site and I am needing some advice on a recent problem that I am having with my 2005 Sport Trac 4.0L (K) - Flex Fuel Vehicle. I have always used Unleaded 87 Octane in my truck, until recently. I ran one full tank of E85 through it, and within 3 or 4 days my truck threw 2 emission codes - bank 1 too rich and bank 2 too rich. Cleared the codes and they came back the same day. I would think that the E85 and the Engine Service Light with Emission Codes are related to one another, since I have never had any problems like this before or any emissions codes before. Not sure if I ruined the O2 Sensors or what??? Has anyone else had this happen to them?