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P0420 Diagnostic Trouble Code Discussion for October 2014

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1998 Chevrolet Metro 1.0L MIL Lamp on, o2s2 VIN: 2C1MR2266W
P0420: Cat effecientcy. ... through emissions test and drove it over 200 miles with "Cata Clean" in the tank. It would not get ready and the rear o2 is following the front. Customer is a working mom with no money. Finally it threw the p0420 again. I get it (I suppose it is my...
October 07, 2014
1998 Chevrolet Metro 1.0L MIL Lamp on, o2s2 VIN: 2C1MR2266W
P0420: Cat effecientcy. ... through emissions test and drove it over 200 miles with "Cata Clean" in the tank. It would not get ready and the rear o2 is following the front. Customer is a working mom with no money. Finally it threw the p0420 again. I get it (I suppose it is my...
October 08, 2014
2007 Subaru Outback 2.5i Basic 2.5L MIL Lamp on VIN: 4S4BP61C27
P0420: Catalyst Efficiency Below Normal (Bank 1). ... car so we have been taking our time with it. I have 2 codes that occur exactly at the same time intemitantly and thats what is throwing me off. p0420 catalyst system efficiency below threshold and p0457 evap emissions con...
October 29, 2014