smog issues with stock ka24de - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Sileighty_DRFT89 · 10-14-2009, 02:16 PM

I recently got reffed and I need my car to pass emissions (modified smog ticket). when I got it tested at the reff yesterday it had failed on HC's and CO's. I've changed the cat, changed plugs, checked timing (good), cleaned egr, replaced 02. I was wondering if anyone has any other solutions to get these to pass on a good number as the reff is really strict. I need some pointers to get the car to pass or I won't be able to drive it on the street any longer

. any help would be appreciated. thanks in advance

***FaLKoN240*** · 10-14-2009, 06:30 PM

http://zilvia.net/f/tech-talk/92533-...-high-nox.html

I know it says nox, but it has other helpful advice for passing smog.

Did you heat up the cat a lot? Maybe the EGR is bad?

Sileighty_DRFT89 · 10-14-2009, 10:57 PM

egr is good. I bansai'd it for a 20 minute drive to the reff at like 5000 lol. I think it was warm enough. thanks for that thread man

blackrms13 · 10-15-2009, 03:53 AM

get an oversized cat...it helps

rioredstang · 10-15-2009, 08:14 PM

if the HC & CO are both high then it is running rich. you need to look at the o2 sensor reading and make sure it is switching. Should switch between .100mv to .800mv. You can use a volt ohm meter to watch the reading. Make sure Mass Air Flow Meter is clean. Make sure there are no vacuum leaks between maf and throttle body. Retarding the timing will lower HC levels. Changing the oil can help a little. I don't know what the levels were to give any more advice.

Sileighty_DRFT89 · 10-17-2009, 12:04 PM

so I've found another issue. my car is an 89 so it should origanally have a single cam. my car came with a dual cam. so the reff said my timing has been set at 15* or should be because they were looking in the 89 service manual which would show the timing of a single cam. the guy that had timed my car must of thought it was a single cam too as it was set at 15*. also the reff had said that the timing was supposed to be set at this. If I tell the reff that the motor has been swapped would I have to get it bar'd?? since its not the motor that originally came in my car?? how would this work??

tofast4u05 · 11-11-2009, 11:19 AM

You shouldn't have to get the car bard because the motor that is in it originally is from a 240sx. It's just out of a newer 240sx which should be OK to swap as long as it passes smog.

10-14-2009, 02:16 PM	#1
Sileighty_DRFT89 Zilvia Addict Join Date: Apr 2008 Location: LaVerne Age: 31 Posts: 960 Trader Rating: (4) Feedback Score: 4 reviews	smog issues with stock ka24de I recently got reffed and I need my car to pass emissions (modified smog ticket). when I got it tested at the reff yesterday it had failed on HC's and CO's. I've changed the cat, changed plugs, checked timing (good), cleaned egr, replaced 02. I was wondering if anyone has any other solutions to get these to pass on a good number as the reff is really strict. I need some pointers to get the car to pass or I won't be able to drive it on the street any longer . any help would be appreciated. thanks in advance __________________ 11:11 333

10-14-2009, 06:30 PM	#2
*FaLKoN240* Super Moderator Join Date: Jun 2004 Location: SF Bay Area Posts: 16,761 Trader Rating: (73) Feedback Score: 73 reviews	http://zilvia.net/f/tech-talk/92533-...-high-nox.html I know it says nox, but it has other helpful advice for passing smog. Did you heat up the cat a lot? Maybe the EGR is bad? __________________ Best way to do business with me? Make your best offer FIRST.

10-14-2009, 10:57 PM	#3
Sileighty_DRFT89 Zilvia Addict Join Date: Apr 2008 Location: LaVerne Age: 31 Posts: 960 Trader Rating: (4) Feedback Score: 4 reviews	egr is good. I bansai'd it for a 20 minute drive to the reff at like 5000 lol. I think it was warm enough. thanks for that thread man __________________ 11:11 333

10-15-2009, 03:53 AM	#4
blackrms13 Post Whore! Join Date: Jul 2007 Location: 626 Posts: 2,591 Trader Rating: (21) Feedback Score: 21 reviews	get an oversized cat...it helps __________________ 91' 240sx Fastback LE

10-15-2009, 08:14 PM	#5
rioredstang Leaky Injector Join Date: Jan 2009 Location: Chattanooga, TN Age: 64 Posts: 81 Trader Rating: (1) Feedback Score: 1 reviews	failed emisions if the HC & CO are both high then it is running rich. you need to look at the o2 sensor reading and make sure it is switching. Should switch between .100mv to .800mv. You can use a volt ohm meter to watch the reading. Make sure Mass Air Flow Meter is clean. Make sure there are no vacuum leaks between maf and throttle body. Retarding the timing will lower HC levels. Changing the oil can help a little. I don't know what the levels were to give any more advice.

10-17-2009, 12:04 PM	#6
Sileighty_DRFT89 Zilvia Addict Join Date: Apr 2008 Location: LaVerne Age: 31 Posts: 960 Trader Rating: (4) Feedback Score: 4 reviews	so I've found another issue. my car is an 89 so it should origanally have a single cam. my car came with a dual cam. so the reff said my timing has been set at 15* or should be because they were looking in the 89 service manual which would show the timing of a single cam. the guy that had timed my car must of thought it was a single cam too as it was set at 15*. also the reff had said that the timing was supposed to be set at this. If I tell the reff that the motor has been swapped would I have to get it bar'd?? since its not the motor that originally came in my car?? how would this work?? __________________ 11:11 333

11-11-2009, 11:19 AM	#7
tofast4u05 Join Date: Sep 2009 Location: Sacramento Age: 33 Posts: 7 Trader Rating: (0) Feedback Score: 0 reviews	You shouldn't have to get the car bard because the motor that is in it originally is from a 240sx. It's just out of a newer 240sx which should be OK to swap as long as it passes smog.

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