O2 Sensor Unplugged?

[Rrydor]

Hi all,

I just bought a '89 Celica GTS a couple months ago. Its running ok, although not very powerful in initial acceleration (seems sluggish when I'm trying to start moving) and idling speed is erratic. I also noticed the 'check engine' light comes on when the ignition is on but the car is not running (I'm pretty sure it's not just a bulb check either). So I looked under the hood and just realized the O2 sensor wire was never plugged into the ECU, it was just hanging there, which may be the problem. Thing is I can't find where to plug it in either - the wire is only about 5" long and doesn't reach anywhere...can anyone help me? I've tried looking in the Haynes manual and haven't found anything there yet. I'm thinking it's a pretty simple problem if I can only figure out where it goes.

Thanks a lot,

Rrydor