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P-0420 - 2003 Dodge Neon

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The definition of code P0420 Is Catalyst Efficiency. You may have an oxygen sensor problem or a catalytic converter problem. Your vehicle has 2 oxygen sensors. Check your oxygen sensors.If they are then you may need a catalytic converter. Depending on your mileage it may be covered under a Dodge emissions warranty. Have it checked by a certified garage first and in the meantime contact your local Dodge dealer and find out the emissions warranty most are 8 yr or 80,000 miles.

Posted on May 20, 2010

    INDIRA KUMAR May 20, 2010

    Dodge Neon has a 5 year 50,000 mile warranty on emissions!



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Po 300 Po 316 Po420 Po430 2004 Ford Taurus. The car idle high or ruff when I start it in the morning but never shut off. After I got tune up it's worse it even shut off after running for a few mins

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Here is a news flash .
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A real smorgasbord!
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1 Answer

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Here is something from a reference guide that we follow at my shop, hope it helps.

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Hello engelhard58
I have attached a link that can give you some of the reasons why your getting that code.I hope you able to get your answer out of that.
Mean of the code=P0420 Catalyst System Efficiency Below Threshold.
Link to site

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