# 2008 Pontiac G8 O2 sensors

**URL:** <https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515>\
**Category:** Maintenance/Repairs\
**Tags:** pontiac, g8\
**Created:** [April 12, 2018, 12:02pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515 "2018-04-12T12:02:34Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![StevenWilson](https://avatars.discourse-cdn.com/v4/letter/s/8e8cbc/32.png) [@StevenWilson](https://community.cartalk.com/u/StevenWilson)\
**Post date:** [April 12, 2018, 12:02pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515/1 "2018-04-12T12:02:34Z")

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I have a road ranger plugged in to keep car in 8 cylinder mode. When un-plugged and in 4 cylinder mode car sets a P0430 code. Car has Kooks long tube headers with high flow cats and full borla exhaust ??? some one said to buy and install 02 sensor extenders on post-cat sensors ???

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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:** [April 12, 2018, 12:57pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515/2 "2018-04-12T12:57:29Z")

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So do you actually have the rear O2 sensors installed? The only extenders I’ve ever seen are wire harnesses to reach the rear O2 sensors that sit farther back than factory. If they are metal collars to move the O2 sensors out of the gas flow, don’t bother, I don’t think that will help a P0430 - catalyst system efficiency is below the required threshold.

That said, you have aftermarket cats on the car and headers so it is very likely they are getting cold when in 4 cylinder mode and THAT is setting the P0430. The extra exhaust volume in 8 cylinder mode keeps the cats hot enough to do their job. If you really want to use the 4 cylinder mode to save gas, I’d suggest wrapping the headers down to the cats with exhaust insulating wrap. Maybe that will work, maybe it won’t. You just have to try it and see.

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**Author:** ![StevenWilson](https://avatars.discourse-cdn.com/v4/letter/s/8e8cbc/32.png) [@StevenWilson](https://community.cartalk.com/u/StevenWilson)\
**Post date:** [April 23, 2018, 2:33pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515/3 "2018-04-23T14:33:21Z")

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My G8 passed emissions with flying colors. The CEL-Adapters work to cancel out Code-PO430.

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**Author:** ![StevenWilson](https://avatars.discourse-cdn.com/v4/letter/s/8e8cbc/32.png) [@StevenWilson](https://community.cartalk.com/u/StevenWilson)\
**Post date:** [April 23, 2018, 2:34pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515/4 "2018-04-23T14:34:26Z")

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Yes they are the metal collars, they WORK.

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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:** [April 23, 2018, 2:38pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515/5 "2018-04-23T14:38:25Z")

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Well I’ll be dipped! Never thought that would work. You learn something new every day. Thanks for the feedback!

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**Author:** ![StevenWilson](https://avatars.discourse-cdn.com/v4/letter/s/8e8cbc/32.png) [@StevenWilson](https://community.cartalk.com/u/StevenWilson)\
**Post date:** [April 23, 2018, 2:48pm UTC](https://community.cartalk.com/t/2008-pontiac-g8-o2-sensors/115515/6 "2018-04-23T14:48:40Z")

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Hey your welcome.