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P0420 Diagnostic Trouble Code Discussion for April 2010

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2003 Lincoln LS 3.9L MIL Lamp on VIN: 1LNHM87A03
P0420: bank 2 cat below threshold. after clearing ml lamp, light will come on after about 15 miles of driving runs and drive ok
April 01, 2010
2005 Kia Rio 1.6L Poor Fuel Economy, MIL Lamp on VIN: KNADC12535
P0420: Catalyst Efficiency Below Normal (Bank 1). This car has been in several times. O2 sensors were replace 2-3 times. final time, original equipment O2 sensors were installed. Code reoccured. After following All-Data and mitchell testing, computer was replaced. Still no solution. Have checked resistance on...
April 07, 2010
2001 Chevrolet Malibu 3.1L MIL Lamp on VIN: 1G1ND52J21
P0420: Catalyst System Bank 1 Low Efficiency. This car had a grand total of 4 cat on it, the first one was a after market and the other were walkers cats. after about 1000 miles or 3months it would eat up a cat and the o2's would be the same and it would have a code po420 The cat will not light up.No wate...
April 22, 2010
2007 Chrysler Town & Country 3.3L MIL Lamp on VIN: 2A46P54L67
P0420: Catalyst Efficiency Below Normal (Bank 1). ... months. Originally we had a lean code and had bad pre cat sensor. After replacing that car was gone for a month. It came back and we replaced the down stream sensor. A month later we replaced the cat. Now it has been another month and we have code P0420 an...
April 22, 2010