If your car is dead won't start, the code 54 is most likely responsible. It means the computer don't know what cylinder is fireing. It either means the camshaft position sensor is bad or the lead from the distributor has no signal.
If your car does start, but runs rough, replace the sensors for the 13 and 23 codes. They deal with how much gas to give the engine.
12 Battery or computer recently disconnected
13* MAP sensor or vacuum line may not be working
23* Incoming air temperature sensor may be bad
54 camshaft sensor/distributor timing