O2 sensor help...

I have a code that my upper pass side o2 sensor is bad..my gas mileage has def gotten worse.. is it possible to just change the one or do I need to change all 4 as they’re pretty expensive.. already tried cleaning them all. 4.0 v6... thanks all!

 

Change the fronts in pairs. The back ones do not affect fuel mileage they only check for catalytic converter efficiency.

 

Thank u, that makes sense. Should help with mileage and get light to go off?

 

If the one is out of whack enough to cause the check engine light it will definitely affect fuel mileage as it used as the feedback to maintain the optimal A/F ratio. The check engine light will required to me manually reset once the sensor is replaced.

 

Ok, I’ll change them both then erase with my code reader. Thank u.

 

Go with Denso. Avoid Bosch

 

Yah that’s what I figured... keep it oem. Thanks!

 

Is it a heater circuit code? Slow repsonse?

Make sure there aren't any fresh air leaks into the exhaust, check the gaskets and connections

 

I have a tiny exhaust leak on my muffler I just noticed the other day... I’ll recheck my scanner and see. I’m pretty sure it read bank 1 sensor 1 though....

 

The only leaks that matter are upstream or around the sensors. Down by the muffler won't affect sensor performance

 

Ok thank ya