How to lower NO emissions ?
#1
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Nov 2001
Location: San Diego, CA
Posts: 1,898
Likes: 0
Received 0 Likes
on
0 Posts
How to lower NO emissions ?
Helping a friend with emissions testing with his '99 LS1.
Everything passed except 'NO' count, which was a good amount over the limit.
What needs to be tweaked to lower the NO counts ? Timing ?
Thanks,
Rob (Bad30th)
Everything passed except 'NO' count, which was a good amount over the limit.
What needs to be tweaked to lower the NO counts ? Timing ?
Thanks,
Rob (Bad30th)
#2
TECH Enthusiast
iTrader: (3)
Join Date: Aug 2005
Location: Castle Rock, CO
Posts: 597
Likes: 0
Received 0 Likes
on
0 Posts
NOX is usually a result of running too lean.
Richen it up a tad...but too rich will increase your HC count.
ideally, you should use a wideband 02 and some loggin tools and figure out what the issue is...
Richen it up a tad...but too rich will increase your HC count.
ideally, you should use a wideband 02 and some loggin tools and figure out what the issue is...
#4
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Nov 2001
Location: San Diego, CA
Posts: 1,898
Likes: 0
Received 0 Likes
on
0 Posts
When I run the HPT scanner on it, it shows the LTRIMs to be right around 0 to -2, so I figured that was good to go...
I will suggest to him to drop the timing a couple of degrees in the 15mph range (where it failed the roller test). His EGR is installed but is showing "incomplete" in the readiness tests.
Thanks for the input, anyone else ?
Rob (Bad30th)
I will suggest to him to drop the timing a couple of degrees in the 15mph range (where it failed the roller test). His EGR is installed but is showing "incomplete" in the readiness tests.
Thanks for the input, anyone else ?
Rob (Bad30th)
#5
Kleeborp the Moderator™
iTrader: (11)
Originally Posted by Bad30th
When I run the HPT scanner on it, it shows the LTRIMs to be right around 0 to -2, so I figured that was good to go...
I will suggest to him to drop the timing a couple of degrees in the 15mph range (where it failed the roller test). His EGR is installed but is showing "incomplete" in the readiness tests.
Thanks for the input, anyone else ?
Rob (Bad30th)
I will suggest to him to drop the timing a couple of degrees in the 15mph range (where it failed the roller test). His EGR is installed but is showing "incomplete" in the readiness tests.
Thanks for the input, anyone else ?
Rob (Bad30th)
On the other issue...I have no idear.
#7
TECH Enthusiast
Join Date: Sep 2004
Location: Omaha, NE
Posts: 564
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by White95TA
The EGR is used to reduce NOx, turning it off would not help.
Trending Topics
#8
TECH Fanatic
Join Date: Aug 2005
Location: Sunny London, UK
Posts: 1,690
Likes: 0
Received 0 Likes
on
0 Posts
Yep, lower combustion temps.
You can also turn your fans on a little earlier. Maybe back timing off a tad. If its closed loop you wont be able to do much to richen it up. Though you might have some luck messing with o2 switch points at the closed loop airflow mode that the test fails at.
Let us know how you go.
You can also turn your fans on a little earlier. Maybe back timing off a tad. If its closed loop you wont be able to do much to richen it up. Though you might have some luck messing with o2 switch points at the closed loop airflow mode that the test fails at.
Let us know how you go.
#9
TECH Apprentice
iTrader: (1)
Join Date: Oct 2003
Location: San Diego, CA
Posts: 328
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Bad30th
Helping a friend with emissions testing with his '99 LS1.
Everything passed except 'NO' count, which was a good amount over the limit.
What needs to be tweaked to lower the NO counts ? Timing ?
Thanks,
Rob (Bad30th)
Everything passed except 'NO' count, which was a good amount over the limit.
What needs to be tweaked to lower the NO counts ? Timing ?
Thanks,
Rob (Bad30th)
#13
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes
on
6 Posts
Anything that raises combustion temps (cylinder pressure,
leanness) will aggravate NOx production. So will swinging
too far into the lean, with the proportional fueling action.
If you see the O2s swinging stop-to-stop there is a good
chance you are spending too much time in the bad place
(both of 'em). If you can make it swing tighter and faster
you will cut all emissions down. I'm no expert on how, but
this is where I'd study up on "what", for starts. Also may
want to be sure you do not have some sort of injector
balance problem (like one drooler makes three lean in the
bank, etc. or vice versa).
leanness) will aggravate NOx production. So will swinging
too far into the lean, with the proportional fueling action.
If you see the O2s swinging stop-to-stop there is a good
chance you are spending too much time in the bad place
(both of 'em). If you can make it swing tighter and faster
you will cut all emissions down. I'm no expert on how, but
this is where I'd study up on "what", for starts. Also may
want to be sure you do not have some sort of injector
balance problem (like one drooler makes three lean in the
bank, etc. or vice versa).
#14
TECH Fanatic
iTrader: (1)
Originally Posted by jimmyblue
Anything that raises combustion temps (cylinder pressure,
leanness) will aggravate NOx production. So will swinging
too far into the lean, with the proportional fueling action.
If you see the O2s swinging stop-to-stop there is a good
chance you are spending too much time in the bad place
(both of 'em). If you can make it swing tighter and faster
you will cut all emissions down. I'm no expert on how, but
this is where I'd study up on "what", for starts. Also may
want to be sure you do not have some sort of injector
balance problem (like one drooler makes three lean in the
bank, etc. or vice versa).
leanness) will aggravate NOx production. So will swinging
too far into the lean, with the proportional fueling action.
If you see the O2s swinging stop-to-stop there is a good
chance you are spending too much time in the bad place
(both of 'em). If you can make it swing tighter and faster
you will cut all emissions down. I'm no expert on how, but
this is where I'd study up on "what", for starts. Also may
want to be sure you do not have some sort of injector
balance problem (like one drooler makes three lean in the
bank, etc. or vice versa).
#16
TECH Fanatic
iTrader: (4)
Join Date: May 2002
Location: Fairview Heights Illinois
Posts: 1,851
Likes: 0
Received 0 Likes
on
0 Posts
FWIW, spark advance makes the most difference to both heat and pressure in the chamber.
If the dyno is really loading you down in that speed range, then dropping the advance in that area of the table will do the trick.
*I learned everything I know from the intra-web, so it must be true*
If the dyno is really loading you down in that speed range, then dropping the advance in that area of the table will do the trick.
*I learned everything I know from the intra-web, so it must be true*