P0420 TWC System Low Efficiency Bank 1
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Pro
Joined: Jun 2007
Posts: 544
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From: Ramona CA
P0420 TWC System Low Efficiency Bank 1
what does this mean and what do I need to do. I heard some rattling and was looking around the car amd I looked at my exhaust tips and found part of my cat by the tips. sounds like I need new cats is this true? car is still running strong.
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Joined: Oct 2002
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From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
TWC = Three Way Catalyst.
Bank 1 = left side.
Code simply means your left cat isn't doing it's job. If you found pieces of it in the exhaust, this might be a good indication why.
As long as the material isn't blocking the exhaust too much, yeah, it will continue to run just fine. But I'd say you need a new cat.
Is the car/exhaust stock?
If it is, the cats are a covered item under the 8yr/80k miles federal emissions warranty for major emissions components, and you might qualify.
Bank 1 = left side.
Code simply means your left cat isn't doing it's job. If you found pieces of it in the exhaust, this might be a good indication why.
As long as the material isn't blocking the exhaust too much, yeah, it will continue to run just fine. But I'd say you need a new cat.
Is the car/exhaust stock?
If it is, the cats are a covered item under the 8yr/80k miles federal emissions warranty for major emissions components, and you might qualify.
