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I need to replace the oxygen sensors in the cats. I've searched online for replacements but some say upstream and others say downstream. Which ones go in the cats? Are there other o2's on out cars? Mine is a 2010 G37S Coupe.
They are connected to the cats. Whatever you do, do not use impact tools to install, or remove the new ones unless you are trashing them. P/N 226A0ET000. A picture is worth 1k words.
Aren't those the post-cat/downstream o2 sensors? The pre-cat or upstream ones are much further up in the engine bay, and harder to reach with regular tools.
If those are post cat/down stream why are they before the catalyst? Do we have 6 sensors total? I thought 2 are on headers which would be difficult. Dumb ? Just sitting at work trying to figure out how i’m going to tap into downstream o2 for ethanol sensor and wideband o2 voltages.
I just realized those are aftermarket cats. The OEM cats sit in much higher in the engine bay, and the pre-cat ones are basically right near the header/manifold flange.
The picture above shows roughly where the downstream ones would be if OEM, but yes, those are indeed pre-cat. There are just four O2 sensors, two for each bank.
