smog help

Ek_Alex

New Member
so i have a 96 civic stock besides the (2.25) piping and dc sport headers CARB legal so i went to take my car to smog it and i failed 3 times today the first time i got on the NOx 15mph 1074 max is 487 and at 25mph 1098 the max is 774 so i replaced my iridium spark plugs with ngk copper and took it in a different place the other guy didn't know what he was doing horrible experience said i had the wrong cat anyways so the 2nd time i took it in i got at 15mph NOx 831 and at 25mph 959 so this time was a bit lower so i ask whats going on smog guy told me it could be my dc sport header CARB legal could be flowing in to much air to the cat and cant handle it so i swapped them out and put my stocks back on 3rd time i got at 15mph NOx 1533 and at 25mph 1551 so it was closing time and i ask his opinion on what it could be he said my car is running a lil cold so he suggested i replace my thermostat so im in the processed of changing it in the morning and changing my oil what could it be i have a new cat stock headers one new downstream o2 my ignition timing is 13btdc on everything else i pass but the emission test i faill a lil help would be appreciative
 

RonJ

Banned
High NOx is generally caused by running either too lean or too hot. Is the engine temp abnormally high when running? If not, start by measuring the fuel pressure or at least replacing the fuel filter. Also make sure the ignition timing is set to spec.

Any CEL codes?
 


Ek_Alex

New Member
what do you mean by running to lean? and no the car temperature is good and the fuel filter is new if i have a leak in the fuel filter can that be causing me to fail cause i kinda notice leaking fuel not much just lil nothing major i just did the oil change changed the thermostat and coolant and installed a new o2 sensor so now i have two new o2 sensors and a cat and i have no cel codes
 

RonJ

Banned
what do you mean by running to lean? and no the car temperature is good and the fuel filter is new if i have a leak in the fuel filter can that be causing me to fail cause i kinda notice leaking fuel not much just lil nothing major i just did the oil change changed the thermostat and coolant and installed a new o2 sensor so now i have two new o2 sensors and a cat and i have no cel codes
Fix the fuel leak and go from there.
 




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