cant pass smog

[s14koukirules]

i took my 1995 s14 ka24de to smog it, but it fail because of high nox, the guy told me it could be the egr system or my cat, i also have the check engine light on because i have a s13 tranny which means it doesn't have a crankshaft position sensor on top of the bell housing,but he said as long as the nox is normal he will pass it for me. the weird thing is that i took out my ecu to check for any codes and the only code i get is 82-crankshaft position sensor don't i have to get 32-egr system and 72-cat. also right now i don't drive my car that much, can that cause my ecu not throw those codes. the day i took it to smog it i just drove it straight to the smog station.thanks

[essforteen]

Its Common for our cars to have high NOX get the FSM and look up and see how to test the EGR.
Next when your car goes for a smog test make sure you drive the car for a min 50 miles highway!,
to make sure the cat heats up properly! then go test it!

[calisfinest240]

I would say egr system is bad. If it were your cat you would most likely fail on all three co, hc, and nox.

[rollout240]

i would too say its your egr system. My car had high nox they told me to change it out blah blah blah, the next test ended up having a higher nox. why? idk. so i moved on to the egr. took it off cleaned it out and cleaned carefully most of the debri inside. Story short the car passed. Try cleaning out the egr.

And yes like eesforteen said. make sure the car is well warmed up run it!! A short drive to the smog shop on these old cars usually equals fail. haha

good luck.

[Katsumbhong]

coat hanger and gasoline work wonders.

[s14koukirules]

Thanks for the info, i m going to tried to clean my egr valve, does anyone know how to take the egr out so i can clean it?

[kamilitaryman]

Yea its easy. Read the FSM.

[s14koukirules]

if my egr system is causing me to fail smog how come my ecu doesn't throw code 32-egr system when doing the diagnostic mode in my ecu?

[Katsumbhong]

if my egr system is causing me to fail smog how come my ecu doesn't throw code 32-egr system when doing the diagnostic mode in my ecu?

Because Nissan wiring and sensors are finicky as fuck!

[s14koukirules]

today i checked my egr valve by lifting the diaphragm up and it does stall, but when i rev the engine the diaphragm doesn't lift, so does this mean that my egr valve works or not?

[idlafie]

S14Kouk,

Sorry for the late reply, (I rarely come on Zilvia now since I've sold my S14 years ago), but did you get your S14 to pass smog yet??

Check the following responses I wrote years ago to fellow listmember smog problems....

You'll have to scroll thru them to see my responses:

http://zilvia.net/f/tech-talk/66696-nearly-stock-ka-didnt-pass-smog-ideas.html

this post tells you how to check & adjust your idle

http://zilvia.net/f/tech-talk/82195-high-idle.html


Just for your information high NO readings are due to a lack of hot air gasses not being recirculated back into your intake manifold. The purpose of recirculation hot exhaust gases back into the intake manifold is to keep combustion temperatures below 2400 degrees Farenheit. NO gasses form when combustion temperates get above 2400 degrees Farenheit. Things to check for are 1). Condition of sparkplugs & wires, 2) Condition of distributor cap & rotor, 3), Check for intake / vacuum leaks 4). Make sure Oxygen & Engine Coolant Temperature sensors are functioning properly. 5). Check the soleniods for the EGR system...they are usually right next to the firewall at the back of the motor. Pulling the valve cover will give you better access. You'll need a Factory Service Manual for directions on how to test & service your EGR system. Also make sure the small "L" shaped hose that runs from the BPT valve to the EGR is not leaking/melted. The BPT valve is what provide vacuum to the EGR valve & opens it while you are driving.

And if you need any more info on Failed Smog, just use the SEARCH function here on Zilvia...look for all threads posted by IDLAFIE. I've helped a lot of people with these types of problems.... You might also want to use the SEARCH function here on Zilvia to find a Factory Service Manual...it will help you to troubleshoot & test all the equipment in your EGR system...Make sure to check your solenoids too....

Hope this helps....

Good luck...

ID

PS:
Seafoam will definitely help in cleaning out the carbon buildup in your intake manifold & combustion chamber.......

[s14koukirules]

thank u for the info i m going to check it out