I HAVE A 1999 TOYOTA CAMRY LE 2.2 LITTER MY ENGINE LITE CAME ON CHECK CAR WITH OBD READER CODE PO420 CAME UP SAYS CATALYST SYSTEM EFFICLENCY BELOW THRESHOLD BANK 1 I REAPLACE OXENGEN CENSOR FOR BANK ON E AND TWO FOUND OUT EMISONS IS CALF STANDER CAN SOME ONE TELL ME WHICH CATALYST CONVERDER MIGHT BE BAD

Pesky PO420 Codes - Eastern Catalytic

www.easterncatalytic.com/education/tech-tips/pesky-p0420-codes/

One of the most annoying is the persistent PO420 diagnostic code (Catalyst System ... not only shows its teeth when the catalytic converter is on the blink, but can also be ... Most, if not all, catalytic converter failures are caused by a problem or ...

P0420 Error Code: Catalyst System Efficiency Below ...

www.obd-codes.com/p0420

Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency ... If they have failed, it is likely due to something else that caused it to fail. ... the catalytic converter is broken or failed, it may be restricting the exhaust which will ...

explaining trouble codes po420 - po421 - Discount Catalytic ...

Check engine light comes on and off, these are indication that there is some error code stored in your vehicles ECM. The engine module computer needs to be scanned. These will give the code and as per the error code the further problem can be detected and confirmed. The engine light indicator blinks or remains steady on dash when engine computer noticed any problem with any engine electrically operated components.

For more help, I suggest you to refer the help links provided below. These will let you know more about which areas to look, check, when there is engine light coming up on dash panel.

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Click the link below: -------

Check Engine Light Reset Procedure?

http://whoisbyme.blogspot.in/2012/06/check-engine-light-reset-procedure.html

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Check Engine Light ON?

http://whoisbyme.blogspot.in/2012/06/check-engine-light-on.html

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Intermittent Check Engine Light?

http://whoisbyme.blogspot.in/2012/06/intermittent-check-engine-light.html

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WHY Check Engine Light On car?

http://schematicsdiagram.blogspot.com/2011/06/check-engine-light-on-car.html

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Check Engine Light, VSC light and Traction Control Light ON?

http://whoisbyme.blogspot.com/2012/06/check-engine-lightvsc-light-and.html

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Check engine light flashing?

http://technoanswers.blogspot.in/2012/02/check-engine-light-flashing.html

Service engine soon Light Turned OFF after Jump Start?

http://whatisbyme.blogspot.in/2012/06/service-engine-soon-light-turned-off.html

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After replacing throttle body the Check engine light starts blinking?

http://technoanswers.blogspot.com/2012/01/after-replacing-throttle-body-check.html

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2005 Chevy Impala: Service Vehicle Soon Warning Light?

http://whoisbyme.blogspot.in/2012/06/2005-chevy-impala-service-vehicle-soon.html

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Malfunction Indicator Light ON

http://whoisbyme.blogspot.in/2012/06/malfunction-indicator-light-on.html

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Check power-train message with orange engine light came on?

http://howtobyme.blogspot.in/2012/02/check-power-train-message-with-orange.html

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2007 Toyota Highlander Hybrid: Yellow Check Engine Light ON dash?

http://whatisbyme.blogspot.in/2012/05/2007-toyota-highlander-hybrid-yellow.html

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1999 Toyota Tacoma: Check Engine Light Read Code P0171?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-tacoma-check-engine-light.html

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Car Runs Fine But Check Engine light is ON?

http://whatisbyme.blogspot.in/2012/05/car-runs-fine-but-check-engine-light-is.html

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Check engine light with codes P2195 and P2197?

http://howtobyme.blogspot.in/2012/01/check-engine-light-with-codes-p2195-and.html

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How to Read Codes from Check Engine Light?

http://schematicsdiagram.blogspot.com/2011/12/how-to-read-codes-from-check-engine.html

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Vehicle smog test failed Due to NO MIL/check engine light?

http://schematicsdiagram.blogspot.com/2011/12/vehicle-smog-test-failed-due-to-no.html

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OBD Code is cleared but check engine light will not RESET?

http://schematicsdiagram.blogspot.in/2012/02/obd-code-is-cleared-but-check-engine.html

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Car jerks while going uphill and Check engine light is ON?

http://schematicsdiagram.blogspot.com/2011/12/car-jerks-while-going-uphill-and-check.html

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Toyota Camry Check engine light flashes while driving?

http://schematicsdiagram.blogspot.in/2012/02/toyota-camry-check-engine-light-flashes.html

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These details will help.

Thanks.

Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency Below Threshold (Bank 1) Probably needs a catalytic converter

Code po573 is cruise control / brake switch circuit A circuit voltage high PO420 catalyst system below threshold, po573 is probably a bad brake circuit / switch problem, PO420 is a bad catalatic convertor for bank 1

If the code has cleared on its own then you need to disconnect the battery and re-connect it. This will clear the codes out of the memory. If you don't want to do this you can go to an auto parts strore and have them hook the little computer up to your car and they can clear out the code as well.

I work at an auto parts store, and i can tell u that it will be the oxygen sensors that is the problem.

The code PO420 you have is Catalyst System efficiency is below threshold bank one. Usually replacing the O2 sensor that's the front most in the exhaust system will cure your problem,

Your Check Engine light is on and you find a P0420 code for a catalytic converter fault. Does that really mean your converter has reached the end of the road and needs to be replaced? A new converter can cost $600 to $1000 or more if a new car dealer or repair shop does the job, or maybe half that amount if you do it yourself. It's an expensive fix that may or may not be necessary. The problem, in most cases, is an emissions issue, not a performance issue that affects the way the engine runs.

A P0420 diagnostic trouble code is a "generic" fault code that is set when the Onboard Diagnostic II (OBD II) system sees a drop in converter efficiency. The OBD II system monitors catalyst efficiency by comparing the switching activity of the upstream and downstream oxygen sensors in the exhaust. The upstream O2 sensor in theexhaust manifold reflects the condition of the exhaust gases as they exit the engine. The downstream O2 sensor in or behind the catalytic converter reflects the condition of the exhaust after it passes through he converter.

The catalytic converter is like an after-burner. It oxidizes (burns) any residual fuel vapors (unburned hydrocarbons or HC) in the exhaust. It also burns any carbon monoxide (CO) in the exhaust. The exhaust must meet federal emission standards, and if a problem exists that causes emissions to exceed the federal limits by 150%, the OBD II system is supposed to catch the fault, set a code and turn on the Check Engine light.

Thanks

P0420 is catalyst system efficiency below threshold (bank 1)

P0440 is evaporative emission control system malfunction

P0441 is evaporative emission control system incorrect purge flow

Replace the catalytic converter.

code po420=catalyst system efficiency below threshold bank #1
code po430=catalyst system efficiency below threshold bank #2
from autozone online
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152800a8b20