1997 Jaguar XK8 engine light and low of power

I have a 1997 XK8 and just a month ago I was driving and when I pressed on the gas, I had it bog down with loss of power and the engine light come on and also the reader states "poor engine performance" I have put some dry gas in the gas tank thinking that it was bad gas. I still have not gone through the tank of gas since it was full and I'm unable to drive it this way because when it gets warmed up, (about 3 miles), this is when I go to excelerate the car slow down and looses power.