power loss whilst driving?

Hi. I have a 200 vectra 1.9 cdti design(150), which has just developed the following problem. Ok driving for approx 3-4 miles then, EXHAUST GASES warning light comes on then power is lost. Still revs ok, but no power at all. Stop for a short interval, then after driving off all is ok for a short while. Have been told that the most common causes of these problems in vauxhall vectra's is something called the EGR VALVE. Does this make any sense with the explanation i have given above. Please help as i have only just bought the car and will be gutted if i have to get rid. Don't mind spending a little to sort out the problem long-term. Thanks.