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P0420 Diagnostic Trouble Code Discussion for March 2015

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2009 Suzuki SX4 2.0L Stall VIN: JS2YB41349
P0420: Bank 1 Catalyst system low efficiency. Has a clicking or ticking noise from top end of engine I pulled the cam cover and do not see anything wrong.It does not sound like rod knock sounds like valve train noise. Timing chains look ok can see the top wear block. it will stall when coming to a stop cu...
March 10, 2015
2005 Chrysler Town & Country Touring 3.8L MIL Lamp on VIN: 2C4GP54L25
P0420: Catalyst Efficiency Below Normal (Bank 1). This is my wife's van. The problem first showed up about 2 1/2 years ago and everything at that time pointed O2 sensors. After going crazy over them I finally bought OEM MOPAR sensors using the emission label ID number to get the correct ones. Numbers matched ...
March 13, 2015
2003 Chevrolet Impala LS 3.8L MIL Lamp on VIN: 2G1WH55K13
P0420: Catalyst System Low Efficiency. Got this impala that has a p0420 and p0128 for thermostat and cat efficiency. I went ahead and slapped a thermostat in it because it was very quick and easy to do. That brought the temperature back up to specs. My question is the p0420. I didnt look at the o2s...
March 23, 2015
2005 Audi A4 1.8L MIL Lamp on, Lack of Power VIN: WAULC68E55
P0420: 16804 Catalyst Bank 1 Operation Below Threshold. ... Vehicle lacks power. Customer claims catalytic converter was glowing red. Was unable to duplicate. Figured out the Secondary Air Injection code; water in pump and a torn elbow near valve cover. Believe the lack of power is the reason P0299 is set. Found TS...
March 26, 2015
2009 Suzuki SX4 2.0L Stall VIN: JS2YB41349
P0420: Bank 1 Catalyst system low efficiency. Has a clicking or ticking noise from top end of engine I pulled the cam cover and do not see anything wrong.It does not sound like rod knock sounds like valve train noise. Timing chains look ok can see the top wear block. it will stall when coming to a stop cu...
March 26, 2015