# How to check for a bad 02 sensor? I'm running rich

**URL:** <https://forums.speedlife.net/t/how-to-check-for-a-bad-02-sensor-im-running-rich/29152>\
**Category:** NYSpeed Automotive\
**Created:** [May 11, 2007, 2:00pm UTC](https://forums.speedlife.net/t/how-to-check-for-a-bad-02-sensor-im-running-rich/29152 "2007-05-11T14:00:08Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![Pauly](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pauly/32/7493_2.png) [@Pauly](https://forums.speedlife.net/u/Pauly)\
**Post date:** [May 11, 2007, 5:13pm UTC](https://forums.speedlife.net/t/how-to-check-for-a-bad-02-sensor-im-running-rich/29152/7 "2007-05-11T17:13:34Z")

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Use a scanner and see if its switching. Or use a dvom and check it. Its early obd1 so i’m not sure if a late model scanner would work(you may need to find someone with an old monitor 3000 or 4000. You should be able to check voltage at idle then bring it up to 2500-3000 and see if there’s a difference

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