Thanks for the code reference.Have you looked into a scan gauge?
ScanGaugeII - Trip Computers + Digital Gauges + Scan Tool
Subaru OBDII codes
Tried to delete my reply as I was thinking of Inova by mistake, but no dice.I have an older version of the 9175 and love it. It reads the codes and also tells you what they are, then allows you to clear them. It came with a book listing all the codes but I've never had to crack it open. I bought it on Ebay new for less than Amazon price.