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Home >> Hummer >> 2009 >> H3 Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - DTC P0324 To DTC P0446 >> DTC P0420 >> Repair Procedures
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Repair Procedures

NOTE: A new converter with less than 100 miles on it may set DTC P0420 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.
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