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What can cause error code p0420 on a 2002 Chevy Impala other than a faulty oxygen sensor or catalytic converter?
Wiki User
∙ 16y ago
This code is generic and is the same on all vehicles. P0420 = Catalyst System Efficiency Below ThresholdCatalyst System Efficiency Below Threshold. This means that the secondary O2 sensor detects that the catalytic converter isn't working as efficiently as it should. This engine code can be triggered by any one of the following:
1.) The catalyst in the catalytic converter is cracked, clogged, or otherwise damaged.
2.) The secondary O2 sensor is malfunctioning.
3.) There is an exhaust leak.
4.) The computer unit is faulty
Wiki User
∙ 16y ago
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Where is the oxygen sensor on a 2000 Chevy Impala?
Probably just in front of, or on the front of the catalytic converter.
How do you replace an oxygen sensor on a 2001 Chevy Impala?
There is 1 before and 1 after the catalytic converter.
What sensor or springs are on the exhaust manifold on 96 Chevy Impala?
It has oxygen sensors before and after the catalytic converter.
Where is the oxygen sensor located on 2002 Chevrolet Impala with 3.9 liter engine?
There is one before the catalytic converter and one after.
Where is the oxygen sensor located on a 2002 Chevrolet Impala 3.9 liter engine?
There is one before and one after the catalytic converter.
Where is the oxygen sensor on the catalytic converter on a 1999 civic ex?
The oxygen sensor on a 1999 Honda Civic is located on top of the catalytic converter. The catalytic converter is under the car.
Where is the down stream oxygen sensor?
Usually after your catalytic converter. Usually after your catalytic converter.
What is the purpose of the oxygen sensor after the catalytic converter?
The second oxygen sensor is now used downstream of the catalytic converter to monitor converter operating efficiency.
Were is the oxygen sensor located on a 2005 Chevy impala?
There is 1 before the catalytic converter and 1 after it. The 1 before is called the upstream and the 1 after is the downstream.
Where is the catalyst efficiency below threshold bank 1 located is it the converter that is on the driver side it is an Audi a4 3.0 liter quattro?
the trouble code you have received actually means that the oxygen sensor is reading that your catalytic converter (which breaks down harmful emissions ) is no longer operating properly. Either the oxygen sensor is faulty and is giving a incorrect reading,which means you must repalce it, or the catalytic converter is faulty, and must be replaced.
Where is the oxygen sensor on a 2003 Mazda Protege?
There is two oxygen sensors. One is located before the catalytic converter is located under the heat sheld. The oxygen sensor after the catalytic converter is found under the catalytic converter (under the car) before the catalytic transfer pipe.
Can a cracked exhaust manifold cause the check engine light to come on?
Yes, it can affect the oxygen sensors and catalytic converter.Yes, it can affect the oxygen sensors and catalytic converter.
