Stock O2 sensor needed?
 

I'm getting the 2.1 ECU and I also want to install a wide band sensor and controller. Can I remove the stock sensor and install the wide band sensor in its place, or do I need to have an extra bung welded to my down pipe and run 2 sensors?

My wide band ( which is the AEM ) said to put the sensor about 30" to 36" down stream from the turbo because of the heat generated from the turbo. So I had to add a bung for the wide band. I'm not sure about other brands of wide bands though. As far as the stock O2 sensor I have no clue so I'm not gonna guess, but I'm sure someone from DTI knows.

you need a 0-1v (narrowband) o2 sensor for the ecu to go into closed loop cruise, it will run fine without it, but you will have worse gas mileage

most wideband controllers also have a 0-1V output intended for the stock o2 sensor input, but like boosted said if you put the wb sensor in the stock location it will get too hot and have shorter lifespan

I left the stock o2 alone, and had a second bung welded in just before my presilencer, have had no problems. make sure it is on the top of the pipe though, so that water doesnt collect in it

Please read the sticky!
https://www.rx7club.com/rtek-forum-168/widebands-what-you-think-you-know-but-dont-577999/

Thanks Everyone. I will keep the stock O2 sensor and have another bung welded down stream for the wideband.