1994 Mercury Cougar - Location of EGR Valve

I have a 1994 Mercury Cougar XR-7 2 Dr Coupe. Check engine light on - car runs rough and eats alot of gasoline. I am a single mother of two - I just got the car back from the garage and spent $461.76 to have the plugs & wires replaced, them they said it was the PCM - and I had that repalced and the car still shows the check engine light and runs rough. Now they are saying it maybe the EGR Valve - MAYBE!!! I have read some articles and think this is something I can do my self, but I can no clue where the EGR valve would be located... Can any one help me! Can some link me to a diaghram? Help Me PLEASE!

Did you ever find the problem. Take car to Advance and have them pull codes.