smog test Inspection help!!
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
smog test Inspection help!!
ok i took the car in and it past, but the NO (PPM) shows MAX should not be over 430 at 15 mph..ok mine showed 236. now it still passed but is this to high?..and if so why.The car is all stock oil changed all the time and i keep it tuned up running great..now at the 25 mph test they did 717 is the MAX and mine was 77, and AVE they said should be 50, and on the 15 mph test AVE should have been 57..but mine was 236 but i still past..now what would make it higher than the norm?..and as far as the rest of the test..like the %co2 and the %02 ..and the HC (PPM) it all showed low..like say it should be AVE HC 9 i showed like 7..and AVE C0 (%) should be 0.02 i showed 0.01..so every thing was nice and low but for the 15mph test witch AVE is 57 and i was at 236.But MAX is 430. so i did pass..Any thoughts on why it would be this high would be great..i would love to know why..or what might make it be this high..Any feed back on this well help me ok?..Thanks. 
Last edited by dbiddle; Aug 24, 2009 at 09:07 PM.
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
Any one that might be out their that does smogs, Might help me out!
Any help is better than no help at all.. some one has had to have had this happen to them befor..if so what was your problem?
Just a few clues would help.. Thanks. dbiddle. 
Any help is better than no help at all.. some one has had to have had this happen to them befor..if so what was your problem?
Just a few clues would help.. Thanks. dbiddle.
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
IL does not even check tailpipe anymore, they just plug into the OBD port.
How old are your plugs/wires. NOx is controlled by the AIR system, maybe yours is not running as well as it could, the valves in them are known to get sticky with age till they finally trigger a "Check Engine".
How old are your plugs/wires. NOx is controlled by the AIR system, maybe yours is not running as well as it could, the valves in them are known to get sticky with age till they finally trigger a "Check Engine".
Tech Contributor
Joined: May 2008
Posts: 3,100
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From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
NOx is produced when peak combustion temperatures are high, and is only controlled by the catalytic converters on the C5.
The AIR system is only used to help the cats heat up after a cold startup, and to reduce HC and CO emissions while the cats are heating up.
If your car is running hotter than normal, NOx emissions will be higher.
Tech Contributor
Joined: Jan 2007
Posts: 19,350
Likes: 1,124
From: Dyer, IN
ok i took the car in and it past, but the NO (PPM) shows MAX should not be over 430 at 15 mph..ok mine showed 236. now it still passed but is this to high?..and if so why.The car is all stock oil changed all the time and i keep it tuned up running great..now at the 25 mph test they did 717 is the MAX and mine was 77, and AVE they said should be 50, and on the 15 mph test AVE should have ben 57..but mine was 236 but i still past..now what would make it higher than the norm?..and as far as the rest of the test..like the %co2 and the %02 ..and the HC (PPM) it all showed low..like say it should be AVE HC 9 i showed like 7..and AVE C0 (%) should be 0.02 i showed 0.01..so every thing was nice and low but for the 15mph test witch AVE is 57 and i was at 236.But MAX is 430. so i did pass..Any thoughts on why it would be this high would be great..i would love to know why..or what might make it be this high..Any feed back on this well help me ok?..Thanks.
I certainly would not put too much thought into this, but a few things can affect the NOx emission.....like the temperature of the cats. I would really like to know what that "average" is based on. Also, there is a range for the NOx values for a reason. Your car is half of what the maximum allowable value is.
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
Interesting..you are trying to figure out why your car passed the emissions test.
I certainly would not put too much thought into this, but a few things can affect the NOx emission.....like the temperature of the cats. I would really like to know what that "average" is based on. Also, there is a range for the NOx values for a reason. Your car is half of what the maximum allowable value is.
I certainly would not put too much thought into this, but a few things can affect the NOx emission.....like the temperature of the cats. I would really like to know what that "average" is based on. Also, there is a range for the NOx values for a reason. Your car is half of what the maximum allowable value is.
Tech Contributor
Joined: Jan 2007
Posts: 19,350
Likes: 1,124
From: Dyer, IN
no im not trying to figure out why my corvette passed..im trying to find out why the NOx emission's would be higher than the norm..And the car runs great, the plugs and wires were done about 25K miles ago and looked good still ,but i did them any way, and changed the oil and filter and air cleaner at the same time..so im not up set it passed, just looking to find out what made the numbers higher ok?..Thanks.
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
NOx is produced when peak combustion temperatures are high, and is only controlled by the catalytic converters on the C5.
The AIR system is only used to help the cats heat up after a cold startup, and to reduce HC and CO emissions while the cats are heating up.
If your car is running hotter than normal, NOx emissions will be higher.
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Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
Interesting..you are trying to figure out why your car passed the emissions test.
I certainly would not put too much thought into this, but a few things can affect the NOx emission.....like the temperature of the cats. I would really like to know what that "average" is based on. Also, there is a range for the NOx values for a reason. Your car is half of what the maximum allowable value is.
I certainly would not put too much thought into this, but a few things can affect the NOx emission.....like the temperature of the cats. I would really like to know what that "average" is based on. Also, there is a range for the NOx values for a reason. Your car is half of what the maximum allowable value is.
Thanks, any help is good help.
Tech Contributor
Joined: Jan 2007
Posts: 19,350
Likes: 1,124
From: Dyer, IN
I cant seem to find the smog for 2 years back, but i did find the one for 4 years back.. And it was then on the NOX (PPM) 185 at 15MPH, And 39 for 25MPH..it was lower..so on the 15MPH test it went up 51 points..And on the 25MPH test it went up 38 points..and i think it was after this test i did the plugs and wires..and the car never gets over 195 to 200 with the A/C on on a hot day out..and it dont use any oil, because its never driven that hard..Just looking for diffrent things to check so next time it dont FAIL!! and if i can i can fix them now. Thanks, any help is good help.
Thanks, any help is good help.At least with the test 4 years ago, you have some sort of a benchmark. Now, I would solicit other Cali forum members that have stock cars to post their numbers for comparison.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
I wish I had your HCs. Here's what my 01 produced a short while back:
http://www.sme044.org/toppage1.htm
http://www.sme044.org/toppage1.htm
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
Wow, what would happen if you failed an emissions test in California....castration? Settle down......you are not even close to failing, and again....there is nothing wrong with your car...keep that in mind.
At least with the test 4 years ago, you have some sort of a benchmark. Now, I would solicit other Cali forum members that have stock cars to post their numbers for comparison.
At least with the test 4 years ago, you have some sort of a benchmark. Now, I would solicit other Cali forum members that have stock cars to post their numbers for comparison.
And your right i will ask forum members out in calif what their reading are on NOx.. Thanks. dbiddle
and thanks for your advice.
Tech Contributor
Joined: Jan 2007
Posts: 19,350
Likes: 1,124
From: Dyer, IN
well if they sound good to you from the last 4 years to now maybe it is nothing to worry about...And the castration part..well thats not going to happen..
And your right i will ask forum members out in calif what their reading are on NOx.. Thanks. dbiddle and thanks for your advice.
And your right i will ask forum members out in calif what their reading are on NOx.. Thanks. dbiddle
and thanks for your advice.
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
Tech Contributor
Joined: Jan 2007
Posts: 19,350
Likes: 1,124
From: Dyer, IN
Plugs are not a common cause for non-compliant NOx readings(which you don't have). Instead, you could be getting carbon deposits in the combustion chamber(which you could use a fuel treatment), and cats loosing their effectiveness as they age. I think you'll get codes for cat efficiency before you ever fail an emissions test due to NOx readings.
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
Plugs are not a common cause for non-compliant NOx readings(which you don't have). Instead, you could be getting carbon deposits in the combustion chamber(which you could use a fuel treatment), and cats loosing their effectiveness as they age. I think you'll get codes for cat efficiency before you ever fail an emissions test due to NOx readings.
dbiddle,
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Thread Starter
Racer
Joined: Sep 2008
Posts: 414
Likes: 1
and thanks for the more input on this, as far as my engine temperature goes any way i check it, its never over 195 to 200 at most, so are you saying i should try and have the engine run cooler than this?. because now every thing is just kept stock temp and all.and its never changed.
Thanks for your input, dbiddle.
