Stalling

volvo
850

#1

I have a 1996 volvo 850. all of the sudden it started stalling when i take my foot off the gas. it always starts back up, but acts like its flooded or something. it doesn’t do it every time, but pretty close. It’s also getting poor gas mileage and i noticed the area around the tail light and bumper near the tail pipe has gotten a little dark. EGR Valve problem?