New exhaust and no O2 sensor

[Stealer Of Souls]

So after years of neglect my exhaust gasket decided to give up the ghost.
It felt like time to give the car the extractors I'd always promised it.

The question came up of whether or not the O2 sensor needed to go back in.
For now I have opted to leave it out as they did not have the little flange on hand to install it all today and it probably needed the wire to be lengthened to actually reach.

So, the car is my AE86.
Small port bottom end. Blue top head. Standard intake and now extractors (from Woolf, so probably koby).
The engine was reconditioned when it was installed (some 5 years ago now?) and has a factory computer.

The question is. What will this do? Will it stuff things up? Should I plan to go back and get the O2 sensor put back in?

The only other thing is that I don't think the O2 sensor actually works. I hooked up a A/F meter (aftermarket dash mounted one) and it has never read anything sensible.

[sergei]

Do you have stock ECU?
If you have stock ECU, then I would suggest running Ox sensor.
If the aftermarket A/F gauge shows you readings all over the place that implies that Ox. sensor is working.
A/F gauges that hook into narrow band sensors are pointless anyway, they will not tell you anything useful, except when you are running in closed loop (ie light throttle) - then the reading will quickly change from rich to lean, back and forth.

[matt dunn]

IMO, if the sensor is a 1 wire sensor it's a waste of time refitting it,

if it's a 3 wire 50/50,

and if it's a 4 wire then best to refit it.