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P0420 Diagnostic Trouble Code Discussion for April 2013

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2010 Buick LaCrosse CXL 3.0L MIL Lamp on VIN: 1G4GL5EG8A
P0420: catalyst efficiency. Vehicle came in for Cat efficiency codes, Scan tested and road tested . when throttle is snapped while graphing o2 sensors the spike in the pattern seems to occur at the same time on pre and after cat sensors. At a recent snap on course it was stated there sho...
April 01, 2013
2003 Volkswagen Jetta GL 2.0L Misfire, MIL Lamp on VIN: 3VWRK69M23
P0420: VAG - 16804 Catalyst Threshold Below Efficiency Bank 1. Original customer complaint: car came in with CEL on & sometimes Blinking. Rough Idle/Misfire, etc. Scanned for codes. retrieved DTC P0300 & P0304. During visual inspection was able to see Cylinder # 4 Ignition wire Arcing on the Cylinder Head. We repl...
April 08, 2013
1998 Honda Accord LX 2.3L Stall VIN: 1HGCG5649W
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... stall that would restart after a few minutes-time ranged from 3-4 minutes to as much as a half hour and it didn't matter if the engine was cold or warm and it would stall on highway, in town and at idle. Of course it wouldn't stall for me! The only code st...
April 09, 2013
2001 Lexus RX300 3.0L MIL Lamp on VIN: JTJHF10U21
P0420: Cat below effeciency bank 1. ... this RX300 that's chewing my head. it's got P0420 CAT BANK 1 ineffecient. replaced the BANK 1 CAT with a BOSAL from worldpac, now the vehicle is back after 2 days with the same code. my genesis scanner is limited won't graph the O2 sensors to know which is...
April 11, 2013
2007 Chevrolet Silverado 2500 HD Classic LT 6.0L Hesitation VIN: 1GCHC24U47
P0420: Catalyst System Low Efficiency. ... code P0174 too lean bank 2. I replaced the b2s2 o2 sensor when I saw a reading of 0 volts intermittently on scan tool. Cleared code and drove to complete monitors for smog check and code P0420 cat efficiency code came on. I cleared that code and drove the ...
April 12, 2013
2007 Chevrolet Silverado 2500 HD Classic LT 6.0L Hesitation VIN: 1GCHC24U47
P0420: Catalyst System Low Efficiency. ... code P0174 too lean bank 2. I replaced the b2s2 o2 sensor when I saw a reading of 0 volts intermittently on scan tool. Cleared code and drove to complete monitors for smog check and code P0420 cat efficiency code came on. I cleared that code and drove the ...
April 15, 2013
2007 Chevrolet Aveo LS 1.6L Stall VIN: KL1TD56647
P0420: Catalyst System Low Efficiency. customer came in said his car would just stall while driving down highway and wouldnt go over like 20 miles a hour he said even when he was driving like 60 it would be like cut car off cause it wouldnt go it doesnt die just wouldnt go ive drove it and it hasnt...
April 22, 2013