Can't clear code

I'm getting a code 23 even though I have tried clearing the code both by removing the taillight fuse and removing the negative battery cable. I didn't start the engine and the code still remains...Therefore, I don't know if I have solved my sensor problem due to not being able to clear the code.

How long to leave the negative battery cable off and anything else to try?
1995 Metro 1.3 sedan automatic.

How long did you leave the negative cable off/tail light fuse out? If I remember right, the service book says to either do one of those two things, plus press the brake pedal a couple times. Easiest thing to do, is to take out the taillight fuse, then press the brake pedal two or three times. Then put the fuse back in in about a minute or so. That usually works for me on my Geo.

How long did you leave the negative cable off/tail light fuse out? If I remember right, the service book says to either do one of those two things, plus press the brake pedal a couple times. Easiest thing to do, is to take out the taillight fuse, then press the brake pedal two or three times. Then put the fuse back in in about a minute or so. That usually works for me on my Geo.
Thanks for the reply...first tried the tail light fuse, did not clear the code, then I left the negative cable off once up to 2 hours, did not clear the code. Tried the Fuse/brake pedal as suggested. Code remains and I have not even started up the engine...strange???

If the code is still there, then there is a code 23 present when you turn the key on. Code 23 is the Manifold Air Temperature (MAT)/Intake Air Temperature (IAT) sensor circuit. The IAT sensor is located in the air intake duct on the four-cylinder models. Make sure the wiring to that sensor is hooked up properly. I don't believe there's a MAT sensor on the Geos, so the problem is your IAT sensor. If wiring seems to be intact, then try to unplug the wiring harness from the sensor, and plug it back in. Then try the code again. If the code is STILL there, then try replacing the sensor. I believe that sensor is only about $30 at Kragen/Schucks/Parts America.

Make sure the wiring to that sensor is hooked up properly.

Turned out to be an exposed wire near the IAT connector. Patched it up and code is now clear. I had to take a really close look at the wires and noticed it. Thanks!