HiGH NOx smog test need any help to pass!! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

dennydizzo · 06-16-2009, 09:32 PM

i have a 1993 nissan 240sx w/stock ka24de..
well i waited for the last day of my driving permit to smog my car and i failed..i smogged my car after driving on the freeway 10 minz and left it running before it was tested so my cat would warm up and work correctly..my results are:

15mph
HC.....Max=88......Measured=57
CO.....Max=0.52...Measured=0.01
NOx...Max=704....Measured=3151
25mph
HC.....Max=53......Measured=28
CO.....Max=0.50...Measured=0.01
NOx...Max=738....Measured=1796

as you can see i failed the NOx with SUPER HIGH numbers..MY NOx is extremely HIGH compared to the other people wtf is up..my CO is really low..is that unusual? is it true about retarding the spark timing will lower nox?

my car drives like a champ with smooth idle at 850rpm

last 8 months replaced,
sparkplug wires,sparkplugs (except in 1st cylinder couldnt get the sucker out,
will not gaping the sparkplugs correctly be an issue?)
oil changed..
87 cheap gas pumped
knockoff muffler
egr is functional and car dies when you block off the bottom with your hand?
no leaks from cataylic converter bought from
a '90 240sx with low supposely low miles

what the FEEZY could be making my car NOx to skyrocket? any help will be greatly appreciated!!need to pass smog ASAP im in CA btw so smog is really really strict here..NEED ANY ADVICE..i dont have tons of cash available currently so i cannot take it to a mechanic so im trying to figure this out on my own!PLEASE HELP!

06-16-2009, 09:32 PM	#1
dennydizzo Zilvia Member Join Date: Jan 2009 Location: SUNNY CA!! Age: 35 Posts: 204 Trader Rating: (4) Feedback Score: 4 reviews	HiGH NOx smog test need any help to pass!! i have a 1993 nissan 240sx w/stock ka24de.. well i waited for the last day of my driving permit to smog my car and i failed..i smogged my car after driving on the freeway 10 minz and left it running before it was tested so my cat would warm up and work correctly..my results are: 15mph HC.....Max=88......Measured=57 CO.....Max=0.52...Measured=0.01 NOx...Max=704....Measured=3151 25mph HC.....Max=53......Measured=28 CO.....Max=0.50...Measured=0.01 NOx...Max=738....Measured=1796 as you can see i failed the NOx with SUPER HIGH numbers..MY NOx is extremely HIGH compared to the other people wtf is up..my CO is really low..is that unusual? is it true about retarding the spark timing will lower nox? my car drives like a champ with smooth idle at 850rpm last 8 months replaced, sparkplug wires,sparkplugs (except in 1st cylinder couldnt get the sucker out, will not gaping the sparkplugs correctly be an issue?) oil changed.. 87 cheap gas pumped knockoff muffler egr is functional and car dies when you block off the bottom with your hand? no leaks from cataylic converter bought from a '90 240sx with low supposely low miles what the FEEZY could be making my car NOx to skyrocket? any help will be greatly appreciated!!need to pass smog ASAP im in CA btw so smog is really really strict here..NEED ANY ADVICE..i dont have tons of cash available currently so i cannot take it to a mechanic so im trying to figure this out on my own!PLEASE HELP! __________________ LOVIN ME TOOFODEE!!