# P0420 code still coming back

**URL:** <https://community.cartalk.com/t/p0420-code-still-coming-back/109697>\
**Category:** Maintenance/Repairs\
**Tags:** yukon-xl, gmc\
**Created:** [November 26, 2017, 2:16pm UTC](https://community.cartalk.com/t/p0420-code-still-coming-back/109697 "2017-11-26T14:16:06Z")\
**Posts on this page:** 1\
**Page:** 2

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**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\
**Post date:** [August 19, 2023, 10:49pm UTC](https://community.cartalk.com/t/p0420-code-still-coming-back/109697/21 "2023-08-19T22:49:56Z")

</div>

To start a fresh thread about your Yukon @brandypuckett93_186500 , click “maintenance/repairs” upper left, then “new topic”, upper right. Be sure to include make/model/year/engine/transmission configuration.

[Previous page](https://community.cartalk.com/t/p0420-code-still-coming-back/109697.md?page=1)