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I am hoping I can get some help with my Upstream O2 sensor. It is currently giving me a static reading of about 1 volt. When I rev the engine it drops a bit to ~0.9, spikes up to about 1.4, then levels out back to about 1. From what I know of most cars, this value should be constantly varying when at idle, like a wave sign.
History:
I've had some issues with my O2 sensors and cat in the past. I replaced my cat not long ago with a Magnaflow, and the downstream O2 sensor wasn't working. So I replaced that and it seems to be working fine now. But I still have that issue above with the Upstream.
Idle
After rev
Do I need to replace the upstream O2 sensor as well? Some other issue? Thanks.
The wave sign thing applies to a narrow-band sensor which is very imprecise. That's why it oscillates. The RX8 front sensor is a wide-band, it reads the actual AFR and there is no reason for that to oscillate.
1 on that scale is 1 lambda = 14.7 AFR
It drops to 0 after revving because no fuel is injected while the engine coasts down. All cars do this.
Keep an eye on that magnaflow cat, they tend to not live long attached to a rotary. You can monitor cat temperature via OBD if your downstream O2 is in working order.
03-18-2018, 04:38 PM
