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P0420 Diagnostic Trouble Code Discussion for March 2009

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2002 Pontiac Grand Prix SE 3.1L MIL Lamp on VIN: 1G2WK52J42
P0420: Catalyst System Bank 1 Low Efficiency. ... and steady. Ran diagnostic reader and code of P0420 reported. Would there be anything logical that is causing the CAT to burn up? Is there anything else that I should look at besides the CAT itself?
March 03, 2009
2003 Buick Regal LS 3.8L MIL Lamp on VIN: 2G4WB52K23
P0420: Catalyst System Low Efficiency (Bank 1). This is the third time that the car has come in with this code. We have replaced the converter two other times with carquest units. the temp is same from the front and rear of the converter. There are no missfire counts in the computer the fuel trims are good....
March 05, 2009
2000 Honda Odyssey LX 3.5L MIL Lamp on VIN: 2HKRL1858Y
P0420: Catalyst Efficiency Below Threshold (Bank 1). the dealer is supposed to have a repair for this code 401 - has anyone ever done this modification ?? this was the only code in the system after we cleared it 2 times then on the 3rd we got a 325 and a 400 - van runs perfect
March 09, 2009
2001 Toyota Camry CE 2.2L MIL Lamp on VIN: 4T1BG22KX1
P0420: Catalyst Efficiency Below Normal (Bank 1). Hey everybody. Thanks in advance for any time you can take to respond to this question. Car came in with a code po420. Easy enough to veryify bad cat with rear oxygen sensor wild fluctuation. The problem comes with locating which converter to replace. The upst...
March 09, 2009
2002 Chevrolet Impala LS 3.8L MIL Lamp on VIN: 2G1WH55K22
P0420: Catalyst System Low Efficiency. this code keeps coming back before we warranty the converter has any one else been having this problem when the cat wasn't the fix? should we try another update?
March 10, 2009
2002 Dodge Ram 1500 SLT 5.9L Poor Idle Quality, Hesitation, Surge, Misfire, Poor Fuel Economy, MIL Lamp on VIN: 1D7HU118Z6
P0420: cat eff. code. ... P0420, which is a cat eff. code and a P0351 code which is a coil code. The dealer put a new cat and o2 sensor on about a year ago. About a year ago the customer had the truck stop running on him. come to find out he has put 3 coils in this tuck over the pa...
March 11, 2009
2002 Nissan Sentra SE-R 2.5L no power VIN: 3N1AB51D52
P0420: Catalyst Efficiency Below Normal. ... my shop with a no power problem. It idles fine but as soon as you hit the gas pedal the first time apon starting it revs up to 3500 rpm than drops back down to 700 rpm no matter what the gas pedal is doing. I pulled the 02 sensor out thinking it was clogge...
March 16, 2009
2003 BMW 745Li 4.4L MIL Lamp on VIN: WBAGN63403
P0420: Cat Efficiency Bank 1. We have this BMW with a repeated cat efficiency problem. My trim readings are as follows at idle: STFT 1= -0.7 STFT 2= -0.7 LTFT 1= +9.4 LTFT 2= +9.4 In the freeze frame data which was taken at 60 MPH under a low load, the trims are very similar: STFT 1= +1.6...
March 19, 2009
2003 Toyota Echo 1.5L MIL Lamp on, O2 readings abnormal VIN: JTDAT12303
P0420: Catalyst Efficiency Below Normal (Bank 1). This all started with a p0420. Judging by the mileage on the car, I thought it would be cut-and-dry ... cat replacement. When I hooked up the scan tool to check O2 activity, B1S1 O2 sensor was fixed at 1.27v , rear O2 .1v I back probed the upstream O2 and it w...
March 20, 2009
1998 Honda Civic CX 1.6L MIL Lamp on VIN: 2HGEJ6326W
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... nothing changed,always p0420, is it possible of a leak at the manifold gasket,he is new
March 27, 2009