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Depends on what failed on the emission test. HC? CO? NOx? Combination of these? Check to make sure all the vacuum lines are okay. No cracks or anything.

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โˆ™ 2015-07-15 19:15:21
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Q: If your 1995 Geo Prism has failed emissions tests twice should you replace the oxygen sensor or catalytic converter?
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Related Questions

Why has your car failed the emissions test?

The catalytic converter is most probably broken

What does p0420 mean on your dodge 2006 5.7 truck mean?

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If there are no exhaust leaks or other codes, the catalytic converter has failed. You will need to replace it.

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That depends on the malfunction. A loose cap gap could be fixed very cheaply. A failed catalytic converter can be hundreds of dollars.

Does the check engine light come on if the catalytic converter needs replacing?

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Failed emissions with a P0304 Code on 1997 Acura 25tl the mechanic said this is a catalytic converter problem but is there something else I should test first?

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What about it? All cars will produced NOx. If it failed a e-test it will be because either the catalytic converter is done or the EGR is not working. Or if you have a VR6 then it could be a the secondary air pump not working.

Why does the 96 bronco 5.8 liter have 2 catalytic converters and can I replace it with one high flow and still pass emissions?

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Exhaust leak, failed oxygen sensor, failed catalytic converter.

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What does odc code P0420 mean on dodge Dakota in English?

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What does code P0420 mean for a Chevy s10 v6?

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What does catalyst efficiency below threshold Bank 1 mean?

The catalytic converter for bank one is not working properly. Either a exhaust leak, a failed O2 sensor, or a failed cat.

Why might an '89 Honda Civic fail an emissions test 3 times because of high readings on idling after changing the O2 sensor and catalytic converter?

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My F0rd F150 truck failed inspection with this code P0420. What does this code-P0420 mean?

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What would cause an EGR valve to burn up repeatedly in a Dodge Dakota?

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The exhaust is plugged, most likely a failed catalytic converter.

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You failed to mention the year but I would suspect a plugged fuel filter or a damaged catalytic converter.

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