98 saturn sl2 Flashing coolant light

So flashing low coolant light means the pcm is not recieving data or bad data from the coolant temp sensor. so i replaced ECTS and flushed radiator and coolant tank, unpluged battery reset everything and still get the blinking light. temp gauge works fine engines stays at 1/4 to 1/2, so what else may be wrong, its a manual so what about tts? also car will not pass obd self test, it seems the computer will not "hold memory" and yes i've done the drive cycles. perhaps the coolant issue interfears with the self tests? or a pcm problem? Any suggestions!!!???? i've about exhausted all resources and can't afford some mechanic telling me one thing and charging me an arm!!

Update!!! just ran a few more drive cycles, got into the obd readiness test, said the catalyst not ready and evaperator system not ready. i shut the car off waited awhile checked the readiness test again and same results, COMPUTER IS HOLDING MEMORY. so half why down the road MIL comes on YEAH what the heck is the problem? P0133 (Bank1, Sensor1) so time to change front oxygen sensor? However the low coolant light still blinks!!!Help
!!:banghead:

Coolant light: remove resiviour and clean it with soap and water. If that doesnt help, you need a ne resiviour as the sensor is bad.

P0133 : Yes, a new o2 sensor is needed if the ECTS has been changed and the connector was corrosion free. Bosch universals work, but need to be spliced in.