Does the "check engine" show up on start-up (key on, not ignition)? If not, the most likely cause (and the easiest "disabling" solution) is to get rid of the bulb. I don't know if you can get under the dash to access the backside... if not, need to remove the dash. I suggest getting a repair manual (buy and download from techinfo.subaru.com, or subscribe at alldatadiy.com, which is cheaper but only for one year). I attached a part of it that might be helpful.Picked up my newsed, 98 Forester S. Engine is missing badly, but now CEL. I realized that someone has disconnected it. Can someone tell me how to reconnect. Thanks
Did 98s even come with OBDII plugs? I thought it was 2000 and newer... I could be wrong.If the bulb is burned, but the system is working, an OBD-II scanner will tell you if the Check Engine Light (or Malfunction Indicator Lamp) is 'on'. If the engine is misfiring badly, the seller may have disconnected the bulb deliberately. You may have a legal case, but I bet the seller put 'as-is' on the bill of sale. But it's possible the light burned out on its own, and the previous owner didn't notice the performance issues. (Didn't you notice anything when you test drove it?)
The scanner should also tell you the diagnostic trouble codes (DTCs) set by the computer, which should point to the cause. With luck it may be something simple. If all the cylinders seem to misfire, it could be a bad fuel pump, clogged fuel filter, bad oxygen sensor, bad air flow sensor, clogged fuel injectors, or a tank of really bad gasoline; if particular cylinders are bad, it could be bad coil wires, bad spark plugs, bad coil packs.