# Catalist efficiency below threshold

**URL:** <https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350>\
**Category:** Maintenance/Repairs\
**Created:** [May 22, 2016, 12:34am UTC](https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350 "2016-05-22T00:34:22Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Sloepoke](https://avatars.discourse-cdn.com/v4/letter/s/da6949/32.png) [@Sloepoke](https://community.cartalk.com/u/Sloepoke)\
**Post date:** [May 22, 2016, 12:34am UTC](https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350/1 "2016-05-22T00:34:22Z")

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I was app. 10 miles from home & engine started missing & went into limp mode & yes the light flashed . I limped it home anyway & now have a PO430 code . # 2 spark plug died & caused this , danged plug didn’t have a hundred miles on it since new . Replaced that plug & everything’s fine except that code . Vehicle runs great . Anyone think cataclean or a similar product is worth a try ? I’ve also read an 02 sensor could cause this code .

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**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\
**Post date:** [May 22, 2016, 1:08am UTC](https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350/2 "2016-05-22T01:08:19Z")

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It may take x amount of miles and or starts for the code to clear. Both are possible, no personal experience with cleaners for the cat.

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [May 22, 2016, 1:13am UTC](https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350/3 "2016-05-22T01:13:38Z")

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The flashing Check Engine light was reporting that if you continued to drive the vehicle, there was a possibility that the catalytic converter could be damaged. And if the substrate of the catalytic converter is cracked it reduces the catalyst efficiency.

Some will say replace the down-stream O2sensor. But this is like killing the messenger because you don’t like the news.

> **[P0430 - OBD-II Trouble Code](https://repairpal.com/obd-ii-code-p0430)**
>
> Definition of error code P0430 - Catalyst System Efficiency Below Threshold (Bank 2). Read emissions expert information and diagnostics for fault code P0430

Tester

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**Author:** ![NYBo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nybo/32/17281_2.png) [@NYBo](https://community.cartalk.com/u/NYBo)\
**Post date:** [May 22, 2016, 2:17am UTC](https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350/4 "2016-05-22T02:17:20Z")

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Some people swear by those catalytic converter cleaners in a bottle, others swear at them. Probably won’t hurt. As @Barkydog wrote, the code will continue until a certain number of “drive cycles” occur. You could clear the code with an OBD II reader and see if it returns.

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**Author:** ![Sloepoke](https://avatars.discourse-cdn.com/v4/letter/s/da6949/32.png) [@Sloepoke](https://community.cartalk.com/u/Sloepoke)\
**Post date:** [May 22, 2016, 8:30am UTC](https://community.cartalk.com/t/catalist-efficiency-below-threshold/93350/5 "2016-05-22T08:30:55Z")

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There are a couple brands that get pretty good reviews . Think I’ll try one . I did clear the code & it came back .