You have a 104 motor. Try a search for EGR Tube or 104 EGR tube. There is a tube that goes from the EGR valve around to the intake side that commonly gets clogged up. It can be cleaned but there is a new style tube that is less prone to get clogged. But you'll get a lot from a search, including how tough it is to get to it.

For clearing the code - what sort of diagnostic plug do you have? A 104 motor would normally be a 16 pin but it seems to me your car was partially OBDII compliant.