# Air (oxygen) sensor

**URL:** <https://community.cartalk.com/t/air-oxygen-sensor/22708>\
**Category:** Maintenance/Repairs\
**Created:** [November 29, 2008, 9:04pm UTC](https://community.cartalk.com/t/air-oxygen-sensor/22708 "2008-11-29T21:04:03Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![shady\_lady\_from\_PA](https://avatars.discourse-cdn.com/v4/letter/s/7993a0/32.png) [@shady\_lady\_from\_PA](https://community.cartalk.com/u/shady_lady_from_PA)\
**Post date:** [November 29, 2008, 9:04pm UTC](https://community.cartalk.com/t/air-oxygen-sensor/22708/1 "2008-11-29T21:04:03Z")

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I needed an air sensor about a month ago. My PA service charged me $230. for my 94 Sable.  
  
 My son in AL just paid 600+ to the Toyota dealer for two (2) oxygen sensors–I assume they are what was replaced in mine. Price seems high–perhaps not. My real question–do 2 go out at the same time-is replacing both necessary? Thanks I’m a dummy and need advice.

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**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\
**Post date:** [November 29, 2008, 9:20pm UTC](https://community.cartalk.com/t/air-oxygen-sensor/22708/2 "2008-11-29T21:20:17Z")

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Some cars only have one oxygen sensor.

Others have two, but they don’t necessarily fail at the same time. Some people choose to replace both on the assumption that if one has failed the other will soon, but they don’t HAVE to be replaced together.

Dealers are more inclined to replace both because they can charge for it. Independent mechanics may be content to only replace the sensor that has failed. The car’s computer knows which is good and which is bad.

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**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\
**Post date:** [November 29, 2008, 10:01pm UTC](https://community.cartalk.com/t/air-oxygen-sensor/22708/3 "2008-11-29T22:01:07Z")

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Some have four.

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**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\
**Post date:** [November 29, 2008, 10:12pm UTC](https://community.cartalk.com/t/air-oxygen-sensor/22708/4 "2008-11-29T22:12:40Z")

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Look at these prices for oxygen sensors, and, then, tell me if you paid too much: [http://www.autozone.com/N,16100117/shopping/partTypeResultSet.htm](http://www.autozone.com/N,16100117/shopping/partTypeResultSet.htm)

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**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [November 30, 2008, 1:05am UTC](https://community.cartalk.com/t/air-oxygen-sensor/22708/5 "2008-11-30T01:05:15Z")

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I needed an air sensor … two (2) oxygen sensors–I assume they are what was replaced in mine

No oxygen sensors measure the oxygen level in the exhaust (converter) the air sensors measures the amount of air going to the engine. They are not even close to the same thing.

Ti is a little late now, but you may have had one or two that had to be replaced. Often it is advisable to replace both just to avoid a second trip and paying twice for some of the same labor.