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P0420 Diagnostic Trouble Code Discussion for February 2009

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1995 Ford Taurus LX 3.8L MIL Lamp on VIN: 1FALP5340S
P0420: Catalyst efficiency code. Replace failed converter at 100,000 miles May 2007, cleared code, no problem till again in December 2007 115,000 miles with same code and post 02 sensor reading .3-.5, once again in December 2008 returned code, repalced converter, code returned within 2 weeks....
February 02, 2009
1999 Honda Accord EX 3.0L No Start VIN: 1HGCG2256X
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... my tail on this one . the car was towed to the shop. I tested the igntion no spark . I started checking stuff and realized the green key was flashing on the dash . Alldata was very vague on this so I checked Michells which was much better . Michells leads ...
February 03, 2009
1996 Jeep Grand Cherokee Laredo 4.0L No Start, Surge, Cuts out VIN: 1J4GZ58SXT
P0420: Catalyst Efficiency Below Normal (Bank 1). Vehicle will die intermintently, sometimes restart, occasionally cuts out. I have only seen this happen once and did not have time to test before failure diminished. Primary coil driver code has only shown up once. I am suspecting an ECM fault but am hesitant ...
February 03, 2009
2002 Chevrolet Camaro 3.8L MIL Lamp on VIN: 2G1FP22KX2
P0420: Catalyst System Low Efficiency. what i need to know has anybody came across this problem . i donot see any type of reflash to open the window for the code setting parameters,im looking at alldata, im sure evrybody will send messages back to replace with genuine convertor. but my exhaust man ...
February 07, 2009
2003 Chevrolet Silverado 1500 5.3L MIL Lamp on VIN: 2GCEK19T03
P0420: Catalyst System Low Efficiency (Bank 1). ... air flow code p0101 keeps coming up and now p0420 cat eff code. i replaced intake gaskets full tune i drove this vechicle 80 miles than light came back on same codes i also replace fuel pump and all o2 sensors i really do not know what to do with this thin...
February 18, 2009
1999 Dodge Avenger 2.5L MIL Lamp on VIN: 4B3AU52NOX
P0420: Left Bank Catalytic Converter Efficency. This vehicle has a PO420 code which the scan tool says is left(front) bank cat efficency. It has always been my understanding that PO420 is bank 1 which is the bank with # 1 cylinder in it. This vehicle has # 1 cylinder in the right (rear) bank. Also, I'm conf...
February 24, 2009
1998 Toyota RAV4 2.0L Excessive Emissions, Poor Fuel Economy VIN: JT3HP10V1W
P0420: Catalyst Efficiency Below Normal (Bank 1). ... out there...this rav4 has a p0171 lean code returning daily only 1 time did i see the p0420 the customer has had this to the dealer and they cant figure it out map sensor , o2 sensor have both been replaced fuel pressure has been checked intake smoked, wha...
February 24, 2009
2002 Toyota Echo 1.5L Hesitation, Misfire, MIL Lamp on VIN: JTDAT12302
P0420: Catalyst Efficiency Below Normal (Bank 1). This vehicle was purchaser at auction. Previous history is unknown. Vehicle has a miss under load. Engine light was on with only a PO420 which means the cat is not efficient. Sales manager does not want to put a cat on the car until the miss fire is repaired. ...
February 26, 2009