What does the service code P0420 mean

Asked by Dec 26, 2015 at 04:07 PM about the 2010 GMC Terrain SLE1 AWD

Question type: Maintenance & Repair

3 Answers


Go to: http://www.obd-codes.com/p0420 There is a lot of info on your code and the causes and repair. HTH

3 of 3 people found this helpful.

Its either te o2 sensor or the catalytic converter

2 of 2 people found this helpful.

Visit your local GMC Dealer. Unless you have over 80,000 miles on your Terrain you may be covered by the new vehicle emission control warranty. A P0420 is either going to be the downstream oxygen sensor or the catalytic converter. My experience with this code is it's going to be the catalytic converter. So check with your dealer first. HTH. -Jim

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