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P0420 Diagnostic Trouble Code Discussion for February 2006

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1999 Honda Odyssey EX 3.5L MIL Lamp on VIN: 2HKRL1867X
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... light. check codes and found miss fire code on cylinder 1,2, and 3 cylinders. Also had code for low cat. efficiency. replade bad coils and clear computer. test drove vehicle. code p0420 came back as low cat. efficiency. check o2 sensor and replace due to s...
February 14, 2006
1996 Ford Taurus GL 3.0L MIL Lamp on VIN: 1FALP52U9T
P0420: cat bnk1 efficiency. This car came in with mil on and cat efficiency low on both banks. o2 sensors below the convertors both read 0 always. we replaced the o2's but they still stay at 0. any ideas
February 23, 2006
2001 Chrysler PT Cruiser 2.4L Cuts out VIN: 3C4FY4BB71
P0420: Catalyst Efficiency Below Normal. ... eaten our lunch for about 3 months. It will intermittently shut down on the freeway after about 15 min of driving in any weather conditions. After the shut down it will restart and run again some times all day with out a problem. This started about a month...
February 24, 2006
1996 Chevrolet S10 4.3L Hesitation VIN: IGCCS14X5T
P0420: Catalyst System Low Efficiency. Cleared codes and non have retured while test driving. Thought problem might just be related to fuel pump as this is so common on this motor, CPI, lots of posts with my problems fixed by FP replacement. Truck feels like it has a slight miss while going down th...
February 28, 2006