1997 Mercury Tracer insufficnt egr flow code p0401

I have a code that states insufficent egr flow.there is no vacuum leak and the engine performs flawlessly. What is the chance that the egr valve is the defective part on this car. I removed the valve and cleaned it w carb cleaner.How do I reset the check engine light and if not the egr valve what else could it be?????

Dan