# 2002 Lexus RX 300 - No nox

**URL:** <https://community.cartalk.com/t/2002-lexus-rx-300-no-nox/149288>\
**Category:** Maintenance/Repairs\
**Tags:** lexus\
**Created:** [September 22, 2019, 8:40pm UTC](https://community.cartalk.com/t/2002-lexus-rx-300-no-nox/149288 "2019-09-22T20:40:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Marischloe](https://avatars.discourse-cdn.com/v4/letter/m/b9e5f3/32.png) [@Marischloe](https://community.cartalk.com/u/Marischloe)\
**Post date:** [September 22, 2019, 8:40pm UTC](https://community.cartalk.com/t/2002-lexus-rx-300-no-nox/149288/1 "2019-09-22T20:40:34Z")

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Both nox sensors are not working.

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**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\
**Post date:** [September 22, 2019, 8:42pm UTC](https://community.cartalk.com/t/2002-lexus-rx-300-no-nox/149288/2 "2019-09-22T20:42:21Z")

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How do you know that? Which “both”? I think this car has four O2 sensors.

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**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\
**Post date:** [September 22, 2019, 10:51pm UTC](https://community.cartalk.com/t/2002-lexus-rx-300-no-nox/149288/3 "2019-09-22T22:51:54Z")

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Your car doesn’t have nox sensors . . . however, it does have oxygen sensors, at least 3, probably even 4

And why are you so sure the sensors aren’t working?

And what is your definition of “not working” . . . ?

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**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\
**Post date:** [September 23, 2019, 4:10am UTC](https://community.cartalk.com/t/2002-lexus-rx-300-no-nox/149288/4 "2019-09-23T04:10:44Z")

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Knock sensor failure is not unheard of on this vehicle, I suspect you have faults P0325/P0330.

Replacement is not cheap, a little over $1000. Also there is the possibility of rodent damage to the wiring harness under the intake manifold near the knock sensors.