yea it is and thats exactly where the other plug end is at . Is installing a heated o2 sensor going to make that big of a difference?
Yes it will, it needs to be as close to the engine as possible, and has to stay at 600+ degrees to stay in closed loop, otherwise, it will alternate between open and closed loop....could cause all kinds of gremlins, but you can try it with the regular 1 wire...its better than nothing.
The heated 3 wire sensor, heats up quicker, and stays heated up, so the ecm stays in closed loop, giving the most power and economy. you may also notice that she warms up quicker than usual, saving even more fuel.