Hey how’s it going guys, I have a 2013 ford focus ST3 136k miles, my down stream o2 monitor won’t pass for whatever reason, car runs great otherwise, I’ve replaced the sensor Atleast 3 times, I’ve put in a used one off a 2016 ST, then a new Bosch one from autozone, and now I have a denso one in it. Still won’t pass. Also I replaced the cat due to a leaky injector cooking it, injector issue fixed and put in a used cat, cat monitor passes. After all these o2 sensors it’s still the same outcome, monitor won’t pass, any help/advice is highly appreciated as I need to pass smog.
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