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P0420 fix information

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Good day.i have a 2009 SUBARU Legacy 2.5L special edition.automatic with 75200 miles.i have been getting a check engine light.the code is P0420,Catalyst system efficiency below threshold (Bank 1) ,i do no notice any problem with the car,but is annoying.i use my Actron scanner and erased the code,this will last for 3 or 4 days,sometime a week,and the check engine light comes back with the same code.right now i do not have the money for a new Catalyst.i came by the video of a fix using a 90 degree angle spark plug fouler.Now my question is, any one know if this can work on my car?.i can see that the O2 sensor location in the cat is easy to remove,but before i buy the angle metal fouler i was wondering if anyone here could give me information..thanks you
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This topic again.


It is rarely the cat if the vehicle is running fine. Often one or more of the following: vacuum leak, exhaust leak, failing sensor.


The $5 fouler trick is a simple first place to start if you have determined there are no leaks in your intake/exhaust system.

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