CEL, ECU location and pulling codes

97, quad 4.
mother in law' car, 1 owner, 46-47k

steady cel, she went to chevy few times, temporarily reset, no codes mentioned.

yes, auto zone might work, but i'm more hands-on. is there a way to access the ecu and turn screw, push button, etc. to read flashes on cel for code (yes, you can tell i'm a nissan guy).

i'm assuming this car is OBD-II since it's a 97?

is there a sticky here somewhere with the code cross reference?

thanks in advance.

Go to Autozone and buy a code scanner