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Old 01-30-2018, 05:24 PM
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Default Check engine light on

My 09 H3T check engine light came on, went to autozone for an OBD check, this code came out.
P0420 OBD-II Trouble Code: Catalyst System Efficiency Below Threshold (Bank 1)
Anybody had similar issues and what was the fix?

Thanks!
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Old 01-31-2018, 10:17 AM
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A number of things could be the p0420 issue. Check the rear O2 sensor itself and wiring/connectors or the Catalytic converter is plugged up. those are the major causes of it.
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Old 01-31-2018, 12:57 PM
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Miles on the Odo is always useful info when asking a question.
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Old 02-05-2018, 10:38 AM
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Quote:
Originally Posted by doc olds View Post
miles on the odo is always useful info when asking a question.
167,000
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Old 02-07-2018, 03:24 PM
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My guess at that mileage, which is not a long shot, is it is time for a new Cat. Like Taint said, could also be the rear O2 sensor, or both Cat and O2?

Any reputable exhaust repair facility can put it on a scanner and run it to full operating temp and watch what happens to double check what it needs.

IMHO and experience, Cats go about 140K miles +/- before they toast.
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