O2 sensor draining battery?

Found another problem on my 95 sportage. Even with new battery and clean connections, battery would die if I didn't run the vehicle for a few days. Yesterday I connected an ammeter in series with the battery negative lead and read just around an amp of draw with everything off (and yes, the interior light fuse removed!)
I removed fuses one at a time and when I removed the O2 sensor fuse, current drain went to zero. Left the fuse out for now, seems to run fine but I am wondering what makes it do that? do I just replace the sensor? Is there more than one? where is it located? :screwy:
Any help would be appreciated! thanks in advance!

Found another problem on my 95 sportage. Even with new battery and clean connections, battery would die if I didn't run the vehicle for a few days. Yesterday I connected an ammeter in series with the battery negative lead and read just around an amp of draw with everything off (and yes, the interior light fuse removed!)
I removed fuses one at a time and when I removed the O2 sensor fuse, current drain went to zero. Left the fuse out for now, seems to run fine but I am wondering what makes it do that? do I just replace the sensor? Is there more than one? where is it located? :screwy:
Any help would be appreciated! thanks in advance!

On newer Sportys there are two oxygen sensore. One before and one after the cat converter.

Thanks hvac1000, I located the sensor - it's a 1995 so must only have one. Disconnected the lead going to it, it has 3 terminals. Probing the leads on the sensor side (imagine the plug facing you, with the guide notch on the top) the 2 right terminals are essentially shorted (< 4 Ohms). Does this indicate a failed sensor? I will check on kiatechinfo for any voltage readings I can look for.

thanks!!

Thanks hvac1000, I located the sensor - it's a 1995 so must only have one. Disconnected the lead going to it, it has 3 terminals. Probing the leads on the sensor side (imagine the plug facing you, with the guide notch on the top) the 2 right terminals are essentially shorted (< 4 Ohms). Does this indicate a failed sensor? I will check on kiatechinfo for any voltage readings I can look for.

thanks!!

I believe that might be a heated sensor.

OK, so replacing the O2 sensor fuse and disconnecting the sensor eliminates the draining of the battery, but obviously I am running without the sensor which is not a good thing.
Does anyone know how to find out if the sensor is bad (other than replacing it) or to find out if the electronics that drive it are bad? It seems to me that there shouldn't be voltage on the sensor when the ignition is off...??
I know the sensor could stand replacing anyhow, but I would like to make sure it's not some other problem.

IN any case, good or bad, the sensor is not supposed to be fed 12V with ignition OFF...so the actual location of the problem is somewhere else: THe fuel pump relay feeds the fuel pump and O2 sensor heater(s) using separate contacts. One contact is possibly shorted inside the fuel pump relay: try the amp test with the fuel pump relay removed.

I had a 95 Kia sportage in my shop that was draining the battery overnight. Found it had a parasitic drain caused by the 02 sensor. Turns out someone had changed one of the relays in the under hood fuse box. Both relays in this vehicle are what is called a dual output. Not a typical 5 pin relay so the parts store will always give u the wrong one. The correct part number is a bosch 0332019151