01 Outback H6 VDC, 97 GT wgn w/ ej22, 98 OBW w/ej22
don't do this.these things seem to reset on its own, when the battery is disconnected ... and re-connected.
when you reconnect the battery the alarm system reads this as an attempt to steal the car. and it will disable the the car UNLESS the ignition key is in the ''run'' position.
in newer models, turning the ignition key on and off 3 times will disable the alrm. i don't remember if the same it true for the 90s models.
look here: Subaru Keyless Entry, Security Alarm, Immobilizer Key, Remote Start Systems. Most years and models
i would replace the battery in the remote. if it works some times and not others there is a reason, a weak battery is very possible. another cause may be dirty contacts in the remote. if the problem continues, i would get a replacement off of ebay. any remote that looks like yours will/ should work after it is programmed.