Smog Emission test failuer
Smog Emission test failuer
I recently had a smog test done to my 1999 frontier and didn't pass one portion of the test. The portions that i did pass was the 25mph test CO2, O2, HC, CO, NO. I was ok with the 15mph CO2, O2, HC, CO but where it failed was the NO test.Can somone point me in the right direction
Re: Smog Emission test failuer (joejoe015)
You may try googling about smog tests and see what cause the NO to be off, may just be a tune up or something simple that can cause it. First you have to find out what it means and what causes it. I live in alabama we have no smog tests so NO means nothing to me.
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C-Kwik
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Did the smog tech note and OBDII codes? If so, that might point you in the right direction.
NOx emissions though, are generally a result of high combustion temperatures. The EGR valve (or a cam timing equivalent) is typically what helps reduce the NOx emissions.
You might post up a copy of the report itself as well. Sometimes, other emissions leves can be higher than it should but still within passing range. Short of multiple smog device failures, seeing the broader range of emissions might help to more easily diagnose the source of the problem.
NOx emissions though, are generally a result of high combustion temperatures. The EGR valve (or a cam timing equivalent) is typically what helps reduce the NOx emissions.
You might post up a copy of the report itself as well. Sometimes, other emissions leves can be higher than it should but still within passing range. Short of multiple smog device failures, seeing the broader range of emissions might help to more easily diagnose the source of the problem.
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PEZi
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FN-QR
check to see if your EGR valve is functioning properly... if not then i personally don't really know where to point you
all i know is my NOx gases fail by over 500%!!!!
good thing i don't have to get tested!
all i know is my NOx gases fail by over 500%!!!!
good thing i don't have to get tested!
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dulobast25
- Posts: 8
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- Car: 2000 frontier
Re: FN-QR (PEZi720)
if u have hi nox? make sure the hoses going to and from your egr valve are not clogged or leaking.next check the bpt valve and be sure it has strong vacuum going in and out of it. then check the hoses going to and from the bpt valve for clogs or leaks.
the bpt is located right above the egr and looks like a disk with 2 hoses on top the b esure the hardline from the egr to the exhs manifold isnt clogged or leaking.
between each check the nox should be going down if faulty. we chased down a noix probl;em on a hb for 2 yrs after switching the bpt valve 3 times.
a mod of the bpt valve took nox from 1300 to under 700 in i hr. cats have an effect but try testing b4 replacing.remeber as nox goes down, co2 often goes up.. its a balance
the bpt is located right above the egr and looks like a disk with 2 hoses on top the b esure the hardline from the egr to the exhs manifold isnt clogged or leaking.
between each check the nox should be going down if faulty. we chased down a noix probl;em on a hb for 2 yrs after switching the bpt valve 3 times.
a mod of the bpt valve took nox from 1300 to under 700 in i hr. cats have an effect but try testing b4 replacing.remeber as nox goes down, co2 often goes up.. its a balance