2018 Chevrolet Tahoe — catalyst efficiency code but car drives normally

If it were in my driveway, two 2018 Chevrolet Tahoes can feel identical and have different causes, so measure before you copy someone else's repair. Don't erase codes until someone who can help has seen them. When does it actually happen? This is me being the wet blanket on purpose.

I wouldn't throw parts yet. Capture voltage while the 2018 Chevrolet Tahoe is actually failing — after it restarts you've lost the clue. Save the big job until that test fails. If it doesn't change the out-the-door or the repair estimate, it's noise. Your commute and mine probably aren't the same, but the test still applies. Parking it somewhere I can hear it better next time.