1993 Saturn SW2 Service Engine Soon only at 50 miles and ab

You have a failure some where there is no service reminder on your car.You most likely have a problem with your egr from what you say about above 50 the light come's on.Follow the instruction's i posted and let me know what code's number's you have.I also emailed you the instruction's so you can read them better.

Yes 12 is normal 26 is quad fault or quad circuit which is big which cover's everything from the speedometer to the egr solenoid 32 is egr let's fix that code and see if the 26 come's back. With the engine cold start the engine pop the hose off of the egr solenoid that come's from throttle body and make sure there is a good vacuum source to that hose. Now push up the egr valve from the underside and manually open it as far as you can the engine should stumble and possibly die. If it doesn't then you have a clogged egr port. Before you replace the egr valve or the solenoid I would like you to test them. You will need a hand vacuum pump to test the egr valve and a multimeter to test the egr solenoid. The vacuum pump they rent at auto zone auto part's what you will do is hook the pump up to the egr valve vacuum nipple and pump the pump up to about 25 the gauge should hold and the egr valve should release and not stick open. With the egr solenoid you will have to get the engine hot with the service engine light coming on at above 50 mph like you were saying. Another word's the code is active then unplug the egr solenoid and you will check across the solenoid's terminal's with the multimeter set to ohm's low scale at 200 ohm's scale. Most of the time when there bad you will get a open reading. Let me know what you find.