Help, OBDII-OBDI CEL

Hey guys, just did the OBDII-OBDI swap in my 2k prelude using a 93 VTEC P13 ECU. The car will start but will quickly throw a CEL. I checked it and it came up as 41, which is something about the primary O2 sensor heater. I'm kinda stumped as to why that's coming up. Any suggestions? I've tried several things including disconnecting one O2 sensor since OBI only has 1 but no go.