Catalyst monitoring

2008 INFINITI G35
1,660,003 MILES
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SAMI1064
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My scanner is showing me this on the catalyst monitoring section:
Lean to rich sensor (v)
Meas:5
Min:25
Max:255
Sts:fail
I would like to know if this is a bad cat or o2 sensor?
Feb 21, 2022 at 6:19 PM
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ASEMASTER6371
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Good morning,

Do you have a code that is set?

You determine a bad cat by the reading on the rear O2 sensor. Can you give me that reading?

Roy
Feb 22, 2022 at 6:41 AM
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SAMI1064
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Hello,

Yes, I sure do. It’s p0420. I also smell gas when I turn on the heater, and for the o2 sensor. I have to double check. I have a cheap scanner so hopefully it gives me a reading. I will let you know ASAP.
Feb 24, 2022 at 3:26 PM
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SAMI1064
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The reading for o2S12 was 0.290.
Feb 24, 2022 at 4:26 PM
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ASEMASTER6371
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This sensor should read around.550 constantly and not vary. If it varies, then the cat is bad and needs to be replaced.

https://www.2carpros.com/articles/catalytic-converter-replacement

Roy
Feb 25, 2022 at 12:03 AM
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SAMI1064
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I went today to a shop and was told the catalytic converter at the manifold right side needed to be replaced. I also hear a pressure sound almost like a high-pressure gas gets released from the exhaust area. I saw the muffler was leaking water as well.
Video (Click to enlarge)
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Feb 25, 2022 at 2:47 PM
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ASEMASTER6371
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As I stated before, you need a new catalytic converter.

Roy
Feb 26, 2022 at 2:28 AM