Failed Smog: HC(PPM) and NO(PPM)
01-07-2015, 08:16 PM
#4
Re: Failed Smog: HC(PPM) and NO(PPM)
The O2 levels seem high so there may be an exhaust leak near the O2 sensor causing the generally high HC levels.
The NOx failure suggests the cat also may bad.
The NOx failure suggests the cat also may bad.
01-07-2015, 09:14 PM
#5
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Re: Failed Smog: HC(PPM) and NO(PPM)
I changed the o2 sensor the other day and notice a hairline crack on the manifold. That may be the culprit. Should I buy a new one or could a used one, which I don't think is recommended, would work?
01-07-2015, 09:36 PM
#7
NOx that high indicates low precat exhaust temps, usually from bad cat, sometimes from leaking exhaust valves.
Weld your manifold, then try again, though you may have to change the cat. Might weld will work on your manifold for the test, but brazing is the ideal method.
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Weld your manifold, then try again, though you may have to change the cat. Might weld will work on your manifold for the test, but brazing is the ideal method.
Sent from my Nokia 5190 using IB AutoGroup
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01-09-2015, 11:06 AM
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Re: Failed Smog: HC(PPM) and NO(PPM)
Do you have an infrared temp gun? You could check the temp of the pipes before, at and after the cat to check if it's functioning properly.
01-09-2015, 01:41 PM
#9
Re: Failed Smog: HC(PPM) and NO(PPM)
Also a citric acid bath of your cat can help bring it back. If you pop it off and it's not a melted clogged mess, I'd save a few bucks and try the hot citric acid bath for 8 hours.
You can google citric acid bath catalytic converter and find a lot of good info.
You can google citric acid bath catalytic converter and find a lot of good info.
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