code p420

1942 MERCURY COUGAR
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0811MA
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i get code p420 on my 2000 mrcury cougar 115000 miles, catalyst below treshhold bank 1,after i clear the code it comes back after 6 driving cycles. the car runs fine,does not burn oil, does not run hot and it shows no other codes is there any other item i should check? please advise. thank you :)
Oct 3, 2007 at 1:27 PM
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SERVICE WRITER
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Check for an exhaust leak in front of the cat. If none prepare to replace the cat.
Oct 3, 2007 at 3:27 PM