Can I drive with a bad O2 sensor? (2 part question)

So I have a 2006 Highlander, V6, and it has a bad O2 sensor per a P0037 code. I am currently at school, and can not fix it for another two months. I know I can drive with the bad sensor, but are there any complications to driving with a bad O2 sensor that would force me to cut back on how much I drive (I put about 60-80 miles a week on it)?

Also when I go to replace the sensor I have to replace the set of senors (before and after the cat) or can I just replace the bad sensor? My dad and I have this debate all the time. I argue that if both senors (Bank 1, sensors 1+2) are bad then I would get two codes, therefore I only have to replace one sensor (bank 1 sensor 2). However he argues that when one sensor goes bad the other senor in the bank has failed as well. So who is right, me or my dad?

On question 1, I suspect you can drive it indefinitely with a bad O2 sensor. There may be longer term issues with your emissions, and if you live in a state with required emissions checks, a “check engine” light on may be problematic for registration.

Another concern is, if you leave the O2 sensor as is and the check engine light on indefinitely, you might not know when/if another problem arises. In other words, your check engine light can only come on once, whether you have 1 problem or 10.

As for question 2, I’m not sure. I tend to think that if one sensor has gone bad, the other one might not be far behind. Replacing both at the same time, to my mind, would depend on the cost of the second sensor.

It’s none of my business, but I’d go ahead and get the problem seen to sooner rather than later. But I tend to like to knock down “problems” as they arise rather than letting them snowball.

Good luck.


Bank 1, sensor 2, is the O2 sensor after the catalytic converter.

The only purpose for this sensor is to monitor the catalytic converter efficiency. It has nothing to do with air/fuel control for the engine.

So, it’s not urgent that this sensor be replaced.

You only replace the O2 sensor the code indicates has a problem.


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I do not have to do an emissions check until 2022, and my car has not thrown a code at me for the past three years so I’m good there. And I guess based on what you’re saying for q2 is that while I am in there I might as well replace the set. This helps a great deal! Thank you!

Well, to be clear…

Just because your vehicle hasn’t “thrown a code” in the past 3 years doesn’t mean it won’t “throw a code” tomorrow. What I’m saying is that CEL can only shine on once. If you don’t resolve this issue and get the CEL turned off, you might not know if another issue comes up that would trigger the CEL.

And I’m not necessarily saying to replace both sensors. If it were me, I’d at least ask how much it would cost to replace both. To Tester’s point, though, your mechanic may be able to test or otherwise determine the 2nd sensor is fine.

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