Code p20EE, Service emissions message?

2018 CHEVROLET SILVERADO
129,000 MILES • 6.6L • V8 • TURBO • 4WD • AUTOMATIC
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CKBUMGARDNER
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  • 1 POST
I can’t get rid of the service emissions message to go away. It also displays the code p20EE from an obd2 scan. What can I do to fix this?
Jan 26, 2025 at 2:59 PM
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STEVE W.
  • ✓ASE Certified Mechanic
  • 15,200 POSTS
  • ASE Certified Mechanic
That code is the reason for the light, it is for the NOX reduction system. It can be caused by a failed converter, but a more common cause is water in the DEF or a frozen DEF feed line. You need to use a good scan tool that has the DEF injection system test. If it passes and is injecting the correct amount of DEF, then the converter may be the issue. Then it is a matter of repairing the defective parts.
Jan 26, 2025 at 6:16 PM
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