Another smog thread. Need help sorry - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Rpjohns3 · 02-11-2013, 04:24 PM

Hey everyone Im trying to pass smog right now but having just a little trouble here. I well give you a run down of my set up. Well I have an 89 chasis but have a 91-94 dohc. Was just swapped into my hatch about 2 months ago. I have put new spark plugs, spark wires, and a new oem fuel filter. The cat I have is fairly old and not sure if that has to do with not passing. The engine I have supposedly has 90k+ miles and I believe that because the engine in general is in really good condition to most ka24s out there. Well Ill post my results to give you guys more of an idea of what I need to do.

15 mph test - HC Max 88 Meas 127 / CO Max 0.53 Meas .74 / NO Max 559 Meas 1498
25 mph test - HC Max 65 Meas 28 / CO Max 0.44 Meas .23 / NO Max 516 Meas 1301

More info to include is that I do smell a funny smell after its running for awhile from the drivers seat. Don't know if that has anything to do with this but just thought Id throw it in there. Thank you in advance for any advice or help. Would like some quick responses if that is possible.

Edwin562 · 02-11-2013, 04:52 PM

HC is high usually means your running rich, NOx usually in Ka motors means your running the engine abit warmer than normal.

milto0n · 02-11-2013, 04:56 PM

Had the same problem passing smog on my first hatch. I had swapped a motor in it and took it to smog. Failed with higher NOx and similar HC as yours. Seafoam is your best friend. Let it sit inside your intake manifold for some time and rev it up. More importantly however, will be the fact that all the smoke you will be blowing (and believe me there will be a lot) will allow you to see if there are any exhaust leaks. Once you do this, basic tune up including oil change and o2 sensor should do the trick. Lastly, get that cat nice and hot before taking it to inspection.

Rpjohns3 · 02-12-2013, 12:40 AM

So you're saying9 my engine is running lean? Is there any signs that I can tell that by without using a machine?

Also seafoam and a new o2 sensor I guess is gonna be on the way. Other than that you guys don't think my cat could be causing any of this? Cause I believe the cat is pretty old. Any other replies or info on this subject well be very helpful.

Rpjohns3 · 02-12-2013, 07:57 PM

No responses on the cat?? Cuz I know had these responses but some guy told me a new cat can help me pass aswell

DJZ · 02-12-2013, 08:08 PM

A new cat will pretty much guarantee you pass if you have no exhaust leaks

zerodameaon · 02-13-2013, 12:59 AM

This Cat will work in Cali, except it was about $60 cheaper in 2011 when I bought it. It made my car pass with flying colors.

Rpjohns3 · 02-13-2013, 12:58 PM

Ok UPDATE lol found out my dumbass did not do a thorough enough inspection before smogging. Well my my "downpipe" that connects to the header was missing a bolt. Could that be the problem? Now Im not sure if this happened before or after smog so idk

Rpjohns3 · 02-13-2013, 12:59 PM

When I say it was missing a bolt I basically mean there was an exhaust leak right there

Rpjohns3 · 02-18-2013, 01:21 PM

Hey everyone just went to go somg and failled again. Worse this time too. All I did this time when I went to go smog is was tighten up that exhaust leak I had between the "downpipe" and header. I thought thats why I had failed.
Well here are the numbers and my plans to hopefully pass.

15 mph test - HC Max 88 Meas 130 / CO Max 0.53 Meas .93 / NO Max 559 Meas 2713
25 mph test - HC Max 65 Meas 30 / CO Max 0.44 Meas .35 / NO Max 516 Meas 1270

So as you can see it is a little worse than my first test. So Im planning on putting in a new cat and a new o2 sensor. Any input on this well be very helpful and quick aswell would be even better. Im hoping the new cat and o2 well make it pass, since thats what some of you before suggested.

Rpjohns3 · 02-19-2013, 10:56 AM

Any suggestions at all?????

soryu · 03-16-2013, 04:49 AM

hopefully a new cat will help. i got a new one and the numbers went up.

here's the results, any one got some input on the numbers?
plugs, wires, cap n rotor, o2sensor all around 7months old.
2nd test 3wks later new cat fresh oil 91gas both times.
the car might have been overheating on second one.

02-11-2013, 04:24 PM	#1
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	Another smog thread. Need help sorry Hey everyone Im trying to pass smog right now but having just a little trouble here. I well give you a run down of my set up. Well I have an 89 chasis but have a 91-94 dohc. Was just swapped into my hatch about 2 months ago. I have put new spark plugs, spark wires, and a new oem fuel filter. The cat I have is fairly old and not sure if that has to do with not passing. The engine I have supposedly has 90k+ miles and I believe that because the engine in general is in really good condition to most ka24s out there. Well Ill post my results to give you guys more of an idea of what I need to do. 15 mph test - HC Max 88 Meas 127 / CO Max 0.53 Meas .74 / NO Max 559 Meas 1498 25 mph test - HC Max 65 Meas 28 / CO Max 0.44 Meas .23 / NO Max 516 Meas 1301 More info to include is that I do smell a funny smell after its running for awhile from the drivers seat. Don't know if that has anything to do with this but just thought Id throw it in there. Thank you in advance for any advice or help. Would like some quick responses if that is possible.

03-16-2013, 04:49 AM	#12
soryu Zilvia FREAK! Join Date: Jul 2011 Location: Socal, I.E. Posts: 1,199 Trader Rating: (17) Feedback Score: 17 reviews	hopefully a new cat will help. i got a new one and the numbers went up. here's the results, any one got some input on the numbers? plugs, wires, cap n rotor, o2sensor all around 7months old. 2nd test 3wks later new cat fresh oil 91gas both times. the car might have been overheating on second one. Last edited by soryu; 06-12-2013 at 03:36 PM..

02-11-2013, 04:52 PM	#2
Edwin562 Post Whore! Join Date: Nov 2009 Location: Whittier (562) Age: 34 Posts: 4,721 Trader Rating: (35) Feedback Score: 35 reviews	HC is high usually means your running rich, NOx usually in Ka motors means your running the engine abit warmer than normal.

02-11-2013, 04:56 PM	#3
milto0n Zilvia Junkie Join Date: Jun 2011 Location: Mesa, AZ Posts: 422 Trader Rating: (3) Feedback Score: 3 reviews	Had the same problem passing smog on my first hatch. I had swapped a motor in it and took it to smog. Failed with higher NOx and similar HC as yours. Seafoam is your best friend. Let it sit inside your intake manifold for some time and rev it up. More importantly however, will be the fact that all the smoke you will be blowing (and believe me there will be a lot) will allow you to see if there are any exhaust leaks. Once you do this, basic tune up including oil change and o2 sensor should do the trick. Lastly, get that cat nice and hot before taking it to inspection.

02-12-2013, 12:40 AM	#4
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	So you're saying9 my engine is running lean? Is there any signs that I can tell that by without using a machine? Also seafoam and a new o2 sensor I guess is gonna be on the way. Other than that you guys don't think my cat could be causing any of this? Cause I believe the cat is pretty old. Any other replies or info on this subject well be very helpful.

02-12-2013, 07:57 PM	#5
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	No responses on the cat?? Cuz I know had these responses but some guy told me a new cat can help me pass aswell

02-12-2013, 08:08 PM	#6
DJZ Zilvia Member Join Date: Dec 2011 Location: norcal Age: 31 Posts: 286 Trader Rating: (3) Feedback Score: 3 reviews	A new cat will pretty much guarantee you pass if you have no exhaust leaks

02-13-2013, 12:58 PM	#8
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	Ok UPDATE lol found out my dumbass did not do a thorough enough inspection before smogging. Well my my "downpipe" that connects to the header was missing a bolt. Could that be the problem? Now Im not sure if this happened before or after smog so idk

02-13-2013, 12:59 PM	#9
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	When I say it was missing a bolt I basically mean there was an exhaust leak right there

02-18-2013, 01:21 PM	#10
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	Hey everyone just went to go somg and failled again. Worse this time too. All I did this time when I went to go smog is was tighten up that exhaust leak I had between the "downpipe" and header. I thought thats why I had failed. Well here are the numbers and my plans to hopefully pass. 15 mph test - HC Max 88 Meas 130 / CO Max 0.53 Meas .93 / NO Max 559 Meas 2713 25 mph test - HC Max 65 Meas 30 / CO Max 0.44 Meas .35 / NO Max 516 Meas 1270 So as you can see it is a little worse than my first test. So Im planning on putting in a new cat and a new o2 sensor. Any input on this well be very helpful and quick aswell would be even better. Im hoping the new cat and o2 well make it pass, since thats what some of you before suggested.

02-19-2013, 10:56 AM	#11
Rpjohns3 Leaky Injector Join Date: Apr 2012 Location: Manteca,CA Age: 31 Posts: 114 Trader Rating: (0) Feedback Score: 0 reviews	Any suggestions at all?????