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P0420 Diagnostic Trouble Code Discussion for August 2004

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2000 Honda Civic LX 1.6L MIL Lamp on VIN: 1HGEJ6574Y
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... came in with check engine lamp on. Codes P0132 P0133 P0420 found Flat line B1 S1 Replaced B1 S1 02 with bosch sensor.Checked rear )02 and showed clean digital fast updating wave .Cleared codes test and codes came back,I did know that there was a small crac...
August 10, 2004
1997 Mercury Villager GS 3.0L MIL Lamp on VIN: 4M2V116VDJ
P0420: Catalyst Efficiency Below Normal (Bank 1). ... for any help on this one. This van came into our shop for the first time with a P0420 code in history and current memory and the MIL was on. After scoping the Pre and Post o2 sensors during a steady hot cruise, it revealed that the rear o2 was switching a...
August 11, 2004
1996 Chevrolet C1500 5.7L Misfire, MIL Lamp on VIN: 2GBEC19R5T
P0420: Catalyst System Low Efficiency (Bank 1). Vehicle has a definite bad B1/S2 HO2 sensor. Exhibits a missfire, mostly on cyl's 5, 6 &7. It will occur after it warms up to above 150 deg. F. and shows up in park accel lightly from 2500 to 3000 rpms and driving, on light accel or sustaining speed on sli...
August 12, 2004
2001 Pontiac Grand Prix SE 3.8L MIL Lamp on VIN: 1G2WP52KO1
P0420: Catalyst System Bank 1 Low Efficiency. this vehicle came in no start.map sensor was open and cat was 1oo% restricted.all pids look ok. #420 will reset.is it possible replacement cat is bad?
August 16, 2004