2G Radio didn't loose setting after disconnecting battery

[my dreamt dsm]

Checked my IAC today so that required I remove my battery. After 30 min or so messing, cleaning, and checking my OK IAC (good 31.1 ohms) I installed my battery back on.
Expecting to input the code back on the radio behold, everything was still there. My channels and radio station were still saved on the STOCK RADIO.
Isn't it suppose to reset? The car is running on monitors for the next 40 miles so car still a little sluggish. Is my ecu fried?



... and then read this.
http://www.dsmtuners.com/threads/02-sensor-stop-reading.484339/#post-153462478

 

[bryanwheat]

For the first question, there will be some power stored in the capacitors in the radio for a while that could keep enough power for the memory. For the second part, did you replace the coolant temp sensor, and did you actually test the circuit for the o2 sensor like the guy told you to?