I have a 91 Subaru Legacy L+ with a 2.2 l mfi engine, with distributorless ignition. It runs fine at high RPMs, but idles rough. The check engine light is on, but I can't seem to get the computer to give me flash codes. What's the trick to getting the flash codes? Help me please?
On the driver left side below steering column are two small green plugs that you have to connect. Plug together to bring up OBD1 flash codes. There's also another set of similar black plugs that bring up previously recorded codes that are stored in the ECU(computer) memory.
Once you read your codes and narrow down your problem. You might also check grounds and wire connections. Some sensors operate at low voltages <1vdc so connections have to be good. A shop manual and multimeter will be handy to perform test on faulty electrical components. Look in the emissions section for specific tests on items in question. Good luck.