Mazdaspeed6 destroyed rear o2 sensor

[04rx8]

So my rear o2 sensor is not going to survive the dp install is there going to be any changes in performance or driveabilty? I've herd it won't harm it I've herd of limp mode tales need some light shed plan on doing the diode trick but in the mean time will performance be hindered with no rear o2 sensor?

[erod550]

I'm not sure it will even run without a rear o2. Or you might just get a CEL. All I know is that on all the DP install threads I've seen, quite a few have mangled the o2 sensors because they just won't come out and they all talked about the cost to replace it, nobody said anything about running without one. This is why I was glad to be doing my downpipe install at 10k miles so the o2s came out relatively easily lol.

[chickenwafer]

I'm not 100% familiar with the Speed6, but if it's like any modern OBD-II Mazda, it will have a front WB02 sensor and a rear narrow band 02 sensor.

The front is for engine operation and controls open and closed loop fueling. The rear 02 sensor is simply to detect if the catalytic converter is working. So, without a rear 02, the car should run just fine with no performance effects, just you will have a CEL.

The car can actually run without ANY 02 sensors because the ECU is designed to not leave you stranded (o2 sensors fail). You will just be stuck in open loop fueling so you gas mileage will blow.

Also, it's a pretty common thing for Mazda's it seems for the factory 02 sensors to be cross-threaded. Not sure why but it was on my RX-8 and nearly every RX-8 I've helped work on, as well as 6's and 3's.