You can add an extender to the rear one, which moves the sensor out of the exhaust flow "tricking" the computer into thinking the exhaust flow is cleaner than it is. If that doesn't work I'd replace both O2 sensors first. Check ebay, rockauto or amazon and only buy ACDelco or Bosch. I've replaced two sets in my daughters 2013 in the 70,000miles she's driven it. Super easy to change, you can "rent" an O2 sensor socket at any parts store. Spray with penetrating oil the night before you change it to make it easier.
Specifications These are needed when using a HHO System or a test pipe. They are also used to lean out your vehicle for better gas mileage. Material: Steel. Dimension: Size:
Amazon.com: ITEQ 3/8 Inch Drive by 7/8 Inch Offset Oxygen Sensor Socket, Wire Gate Accesses Sensor from The Side : Automotive
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