I have 96 Saturn with 97k just bought it and was scammed it had a cracked head, replaced motor with a used one but the ses light keeps coming on and it is missfiring some going up hills also I did'nt think I had back speakers but I checked and thier there they just don't work all the wires are hooked up fine they look brandnew if anyone can help

 

You Might want to change the ECTS (Engine Coolant Temp Sensor) if you go to your local Saturn dealer ask for part number 21025106 it runs anywhere from 15 to 20 dollars also change the O2 sensor the one located in the front of your car it has one wire if you open your hood and look down you should see the one wire thats the O2 sensor you can get that at your local auto parts store its a Bosch(brand) part number 11027 it runs anywhere from 17 to 25 dollars you might be asking yourself why change the ECTS well it does alot more for your car than just sense what your coolant temp is trust me I changed the above mentioned parts and it was like I bought a new car.