I have a 95 2.5L V6 Contour. My CEL has been coming on sporadically. Sometimes I can drive without it ever coming on and other times it stays on for days. I checked the codes. In the KOEO test I got a 1-1-1 or ok. In the memory I get a 3-3-2. I know this has something to do with the EGR. What is this and what do I need to do?