Failed Emissions Test
Thread Starter
Instructor
Joined: Jun 2005
Posts: 231
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From: Waterbury Connecticut
Failed Emissions Test
I took my car for it's biannual emmisions test as required by CT law and it failed because the NOx was too high at 905 and the limit is 614.My CO% came in at 0 (Zero) which I find strange, with a limit of .28. Anybody have an ideas as to how I can get the NOx down?? I'm at a loss here. I have a 1986 stock L98 with a 2 year old complete exhaust system that passed with flying colors 2 years ago and I've only put a few thousand miles on the car since then
Last edited by papidos; Sep 11, 2006 at 07:30 PM.
Le Mans Master
Joined: Dec 2002
Posts: 6,715
Likes: 2
From: Santa Teresa New Mexico
Originally Posted by papidos
I took my car for it's biannual emmisions test as required by CT law and it failed because the NOx was too high at 905 and the limit is 614.My CO% came in at 0 (Zero) which I find strange, with a limit of .28. Anybody have an ideas as to how I can get the NOx down?? I'm at a loss here. I have a 1986 stock L98 with a 2 year old complete exhaust system that passed with flying colors 2 years ago and I've only put a few thousand miles on the car since then
Do this search, "high nox readings".
Egr
Lean fuel mix.
improper spark ad.
Thermostaic air heator stuck in the heat position.
Missing or damaged codl air duct.
Combustion chamber deposits.
Bad Cat.
www.interro.com "high nox reading".
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
To pass the test.
Back off the base timing two degrees.
Add a pint or two of denatured alcohol to the fuel.
I posted this fix a while back when my DD passed with this trick.
When you get home turn the timing back to 6 degrees..
Back off the base timing two degrees.
Add a pint or two of denatured alcohol to the fuel.
I posted this fix a while back when my DD passed with this trick.
When you get home turn the timing back to 6 degrees..
Thread Starter
Instructor
Joined: Jun 2005
Posts: 231
Likes: 0
From: Waterbury Connecticut
Originally Posted by redwing76
Do this search, "high nox readings".
Egr
Lean fuel mix.
improper spark ad.
Thermostaic air heator stuck in the heat position.
Missing or damaged codl air duct.
Combustion chamber deposits.
Bad Cat.
www.interro.com "high nox reading".
Egr
Lean fuel mix.
improper spark ad.
Thermostaic air heator stuck in the heat position.
Missing or damaged codl air duct.
Combustion chamber deposits.
Bad Cat.
www.interro.com "high nox reading".
Txs for the info. My internet went down for a day and I felt like my right arm fell off. I do some investigating into this. I have until April to get the car to pass. 
Thread Starter
Instructor
Joined: Jun 2005
Posts: 231
Likes: 0
From: Waterbury Connecticut
Originally Posted by JrRifleCoach
To pass the test.
Back off the base timing two degrees.
Add a pint or two of denatured alcohol to the fuel.
I posted this fix a while back when my DD passed with this trick.
When you get home turn the timing back to 6 degrees..
Back off the base timing two degrees.
Add a pint or two of denatured alcohol to the fuel.
I posted this fix a while back when my DD passed with this trick.
When you get home turn the timing back to 6 degrees..
I'll may give this a try. It sounds easy enough. Pardon my ignorance but What the heck is denatured alcohol and where can I get it? How soon after I back off the timing and add the stuff should I take it for the re-inspection? Should I drive it for a while before testing? Txs
Thread Starter
Instructor
Joined: Jun 2005
Posts: 231
Likes: 0
From: Waterbury Connecticut
Originally Posted by jserio
Mine i put new O2 sensors and 2 new cats. Passed no problems. This was after failing horribly.
