HiGH NOx smog test need any help to pass!! - Page 2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

S-Nation S13 · 07-09-2009, 08:01 AM

nope as per FSM timing is 20' btdc with +/- 2' look on page 29 under the EF & EC

dennydizzo · 07-09-2009, 07:55 PM

ok so instead of taking out my egr and cleaning it i got another catalytic converter and hooked it to my car and took it to a smog shop(a no pass no pay place) to see how the new numbers will look...turns out i still failed due to high nox at both speeds only went down about 200..

so after avoiding removing and cleaning my egr looks like i have to..and ive read that retarding the timing will reduce NOx numbers..this is correct? and how much can i lower it without damage..

BlazedGlory · 07-09-2009, 08:17 PM

Sorry to be a smartass, buy why ask for help if you don't want to hear any solutions? I still say check out the EGR system. It may not be that the valve itself is clogged, it may just not be operating at all. Who knows. That would still be the best place to start unless you want to keep throwing parts at the problem. If it is all good, at least that will be eliminated from the very good possibility list.

dennydizzo · 07-09-2009, 09:15 PM

Quote:

Originally Posted by BlazedGlory

Sorry to be a smartass, buy why ask for help if you don't want to hear any solutions? I still say check out the EGR system. It may not be that the valve itself is clogged, it may just not be operating at all. Who knows. That would still be the best place to start unless you want to keep throwing parts at the problem. If it is all good, at least that will be eliminated from the very good possibility list.

oh no doubt im going to take apart my egr..i just wanted to rule out the catalytic since its easier to remove than the egr..but now im just wondering if retarding the timing will help me out lowering the NOx level along with cleaning or replacing the egr..

BustedS13 · 07-10-2009, 05:11 PM

when my state still had emissions testing, i once unplugged an injector and let them run it on three cylinders to pass with flying colors.

dennydizzo · 07-11-2009, 05:35 PM

Quote:

Originally Posted by BustedS13

when my state still had emissions testing, i once unplugged an injector and let them run it on three cylinders to pass with flying colors.

r u serious?will that actually work?

BustedS13 · 07-12-2009, 02:38 AM

Quote:

Originally Posted by dennydizzo

r u serious?will that actually work?

it worked for me.

dennydizzo · 07-17-2009, 10:11 PM

okay so i ended up taking apart my egr and cleaned the hell outta it..it was filled with alot of black carbon crap and i ended up buying a brand spanking new catalytic converter and changed my o2 sensor..my results were:

15mph
HC.....max=88.....measured 30
cO.....max=0.52...measured 0.03
NO.....max=704....measured 27

25mph
HC.....max=53.....measured 16
CO.....max=0.50...measured 0.04
NO.....max=738....measured 5

finally passed with Flyin colors...thanks everyone for their suggestions and output!!

S-Nation S13 · 07-18-2009, 12:13 AM

lol thats whats up ..but i think you could of passed with out the new cat but anyways its something that you dont have to replace down the road..hehe

BlazedGlory · 07-18-2009, 05:45 AM

Agreed =P. Well, he'll have to replace it down the road when it fails again =P

dennydizzo · 07-18-2009, 08:54 PM

Quote:

Originally Posted by BlazedGlory

Agreed =P. Well, he'll have to replace it down the road when it fails again =P

iF...iF it fails!!

BlazedGlory · 07-19-2009, 06:29 AM

=P All I'm saying is if you had to replace it once you will have to again. Everything fails at some point. That is why I'm so gungho about diagnosing problems. If you replace something that hasn't yet failed you miss out on some of its usable life and the new part will fail at some point as well.

handinpants · 07-20-2009, 03:10 AM

Your nox levels are high because something in your setup is causing it to run lean and therefore increasing the combustion temps, also you want to fill up 91 octane, maybe buy a new cat and clean the egr, or you can write down the cost for all this, and compare it to paying for a dirty smog and go for the cheaper of the two.

But I recommend you go the legal route

Seikenman · 08-01-2009, 12:25 AM

Congrats on passing your emissions test. About your knock sensor code. You were getting it because you were running 87 regular gas. The dohc 240's need to run 91. You can run 87 but the sensor will detect knock, throwing the knock code, and retard the timing

BustedS13 · 08-01-2009, 04:02 AM

ha ha ha. i capped off my EGR with a chunk of license plate, and i'm about to get an exhaust fabbed up from the header back with no cat.

god i love not dealing with bullshit

miklos · 09-09-2009, 04:59 AM

Timing at 15 is the factory setting

modulation · 10-11-2009, 09:52 PM

I'd bet you had a pre-cat exhaust leak.
I had similar problems (really high nox, low hydrocarbons.)

Turned out to be a exhaust leak right before my cat.

miklos · 10-22-2009, 06:25 AM

I pulled out my egr after running seafoam through the throttle body and found carbon caked inside the manifold.
My egr solenoid had no ground and the vacuum hoses were melted back there on an SOHC.

miklos · 11-09-2009, 01:00 AM

I just failed for the 3rd time.
After the 2nd time:
I replaced the spark plugs and plug wires, O2, EGR solenoid, cleaned out the EGR ports, 2 new fuel injectors, new vacuum hoses, and the MAF.

15mph NOX 2803
25mph NOX 1276
15mph CO .87

Do you think a new cat would fix all of this?

*s13silvia123* · 11-09-2009, 01:06 AM

change your motor oil helps reduce nox. new oil helps the motor work less and creates less nox.

where i use to live use to have smogging and i failed on NOX so i changed my motor oil and went back and passed with flying colors.

miklos · 11-09-2009, 06:22 PM

Oil was changed 5 weeks ago. I'm sure the Cat must be bad causing the NOx to be high

*DreamN* · 11-09-2009, 06:25 PM

Are you getting any codes at all? How's your idle?

Typically when a cat is bad all three areas are higher than normal.

miklos · 11-09-2009, 08:20 PM

I was getting a code for the EGR temp sensor but the light has been off for a week. Idle is good.

07-09-2009, 08:01 AM	#31
S-Nation S13 Zilvia Junkie Join Date: Jan 2008 Location: 760 Oside representin' Age: 23 Posts: 425 Trader Rating: (2)	nope as per FSM timing is 20' btdc with +/- 2' look on page 29 under the EF & EC __________________ jspecs13.blogspot.com

07-09-2009, 07:55 PM	#32
dennydizzo Zilvia Member Join Date: Jan 2009 Location: SUNNY CA!! Age: 21 Posts: 201 Trader Rating: (4)	ok so instead of taking out my egr and cleaning it i got another catalytic converter and hooked it to my car and took it to a smog shop(a no pass no pay place) to see how the new numbers will look...turns out i still failed due to high nox at both speeds only went down about 200.. so after avoiding removing and cleaning my egr looks like i have to..and ive read that retarding the timing will reduce NOx numbers..this is correct? and how much can i lower it without damage.. __________________ LOVIN ME TOOFODEE!!

07-17-2009, 10:11 PM	#38
dennydizzo Zilvia Member Join Date: Jan 2009 Location: SUNNY CA!! Age: 21 Posts: 201 Trader Rating: (4)	okay so i ended up taking apart my egr and cleaned the hell outta it..it was filled with alot of black carbon crap and i ended up buying a brand spanking new catalytic converter and changed my o2 sensor..my results were: 15mph HC.....max=88.....measured 30 cO.....max=0.52...measured 0.03 NO.....max=704....measured 27 25mph HC.....max=53.....measured 16 CO.....max=0.50...measured 0.04 NO.....max=738....measured 5 finally passed with Flyin colors...thanks everyone for their suggestions and output!! __________________ LOVIN ME TOOFODEE!!

07-18-2009, 12:13 AM	#39
S-Nation S13 Zilvia Junkie Join Date: Jan 2008 Location: 760 Oside representin' Age: 23 Posts: 425 Trader Rating: (2)	lol thats whats up ..but i think you could of passed with out the new cat but anyways its something that you dont have to replace down the road..hehe __________________ jspecs13.blogspot.com

11-09-2009, 01:00 AM	#49
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 205 Trader Rating: (0)	Failed again 3x I just failed for the 3rd time. After the 2nd time: I replaced the spark plugs and plug wires, O2, EGR solenoid, cleaned out the EGR ports, 2 new fuel injectors, new vacuum hoses, and the MAF. 15mph NOX 2803 25mph NOX 1276 15mph CO .87 Do you think a new cat would fix all of this?

07-09-2009, 08:17 PM	#33
BlazedGlory Zilvia Member Join Date: Jan 2003 Location: Canton, GA Posts: 296 Trader Rating: (0)	Sorry to be a smartass, buy why ask for help if you don't want to hear any solutions? I still say check out the EGR system. It may not be that the valve itself is clogged, it may just not be operating at all. Who knows. That would still be the best place to start unless you want to keep throwing parts at the problem. If it is all good, at least that will be eliminated from the very good possibility list.

07-10-2009, 05:11 PM	#35
BustedS13 In time-out for misbehaving. Join Date: Jan 2004 Location: STL Age: 25 Posts: 7,862 Trader Rating: (0)	when my state still had emissions testing, i once unplugged an injector and let them run it on three cylinders to pass with flying colors.

07-18-2009, 05:45 AM	#40
BlazedGlory Zilvia Member Join Date: Jan 2003 Location: Canton, GA Posts: 296 Trader Rating: (0)	Agreed =P. Well, he'll have to replace it down the road when it fails again =P

07-19-2009, 06:29 AM	#42
BlazedGlory Zilvia Member Join Date: Jan 2003 Location: Canton, GA Posts: 296 Trader Rating: (0)	=P All I'm saying is if you had to replace it once you will have to again. Everything fails at some point. That is why I'm so gungho about diagnosing problems. If you replace something that hasn't yet failed you miss out on some of its usable life and the new part will fail at some point as well.

07-20-2009, 03:10 AM	#43
handinpants BANNED Join Date: Feb 2008 Location: los Angeles Age: 27 Posts: 1,563 Trader Rating: (26) Rides Gallery: handinpants	Your nox levels are high because something in your setup is causing it to run lean and therefore increasing the combustion temps, also you want to fill up 91 octane, maybe buy a new cat and clean the egr, or you can write down the cost for all this, and compare it to paying for a dirty smog and go for the cheaper of the two. But I recommend you go the legal route

08-01-2009, 12:25 AM	#44
Seikenman Join Date: Dec 2005 Location: New Jersey Posts: 24 Trader Rating: (1)	Congrats on passing your emissions test. About your knock sensor code. You were getting it because you were running 87 regular gas. The dohc 240's need to run 91. You can run 87 but the sensor will detect knock, throwing the knock code, and retard the timing

08-01-2009, 04:02 AM	#45
BustedS13 In time-out for misbehaving. Join Date: Jan 2004 Location: STL Age: 25 Posts: 7,862 Trader Rating: (0)	ha ha ha. i capped off my EGR with a chunk of license plate, and i'm about to get an exhaust fabbed up from the header back with no cat. god i love not dealing with bullshit

Sponsored Links
Remove these by purchasing a Premium Membership with Zilvia.net!

09-09-2009, 04:59 AM	#46
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 205 Trader Rating: (0)	Timing at 15 is the factory setting

10-11-2009, 09:52 PM	#47
modulation Join Date: Apr 2008 Location: San Jose Posts: 36 Trader Rating: (0)	I'd bet you had a pre-cat exhaust leak. I had similar problems (really high nox, low hydrocarbons.) Turned out to be a exhaust leak right before my cat.

10-22-2009, 06:25 AM	#48
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 205 Trader Rating: (0)	I pulled out my egr after running seafoam through the throttle body and found carbon caked inside the manifold. My egr solenoid had no ground and the vacuum hoses were melted back there on an SOHC.

11-09-2009, 01:06 AM	#50
s13silvia123 Premium Member Join Date: May 2006 Location: where waldo is Age: 28 Posts: 2,106 Trader Rating: (2)	change your motor oil helps reduce nox. new oil helps the motor work less and creates less nox. where i use to live use to have smogging and i failed on NOX so i changed my motor oil and went back and passed with flying colors. __________________ 18g and 20g turbo users click on me http://zilvia.net/f/tech-talk/261219-18g-20g-turbo-users.html

11-09-2009, 06:22 PM	#51
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 205 Trader Rating: (0)	Oil was changed 5 weeks ago. I'm sure the Cat must be bad causing the NOx to be high

11-09-2009, 06:25 PM	#52
DreamN Premium Member Join Date: Nov 2006 Location: SoCal (818) Mon★ Rep Power: ∞ Age: 24 Posts: 8,009 Trader Rating: (29) Rides Gallery: DreamN	Are you getting any codes at all? How's your idle? Typically when a cat is bad all three areas are higher than normal. __________________

11-09-2009, 08:20 PM	#53
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 205 Trader Rating: (0)	I was getting a code for the EGR temp sensor but the light has been off for a week. Idle is good.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode