Do I need my O2 sensors?

[fivemustangs]

Hey! I am currently doing a t5 swap in my 91 GT and noticed when i was under the car that the previous owner disconnected the O2 sensors, because the starter was in the way of one of the sensors. My question being, should I weld in a new bung and replace the sensors? Or should I leave them off? I did some searching and got mixed reviews, I just want this car to feel like it has a bunch more balls, then before I dropped my slipping AOD.
Thanks!

 

[oz]

If you're fuel injected you need them.

They provide feedback to the computer which it uses to adjust fuel flow (mixture)... without them - frankly, I'm surprised it runs.

If you're running a carb, no, you don't need them.

 

[HISSIN50]

Without them it should run pretty rich.

 

[Mustang5L5]

Yes you need them.

 

[fivemustangs]

Well that solves that. I put them on today and imagin that......The car runs better! Thanks guys!

 

[njoliver]

your fuel mileage will be a ton better to