NO (PPM) Failing Smog Tests
03-02-2009, 09:38 PM
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NO (PPM) Failing Smog Tests I am having a problem passing smog. I'm not sure if this is where I should post but I'm hoping that someone can give me some insight on my problem. Any information will be greatly appreciated.
I went to get the somg test and came up with these numbers
15 mph @ 1971 RPM
MAES %CO2.... 12.9
MAES %O2...... 2.3
HC (PPM) Max.. 51 (I scored 57)
CO % Max....... 0.48 (I scored 0.42)
NO (PPM) Max.. 419 (I scored 843)
25 mph @ 1778 RPM
MAES %CO2.... 13.1
MAES %O2...... 1.9
HC (PPM) Max.. 35 (I scored 58)
CO % Max....... 0.46 (I scored 0.51)
NO (PPM) Max.. 709 (I scored 884)
Needless to say I failed. I welded 2 new cats and I passed everything except the "NO (PPM)." These were the scores I received the second time around...
15 mph @ 1318 RPM
MAES %CO2.... 13.1
MAES %O2...... 2.2
HC (PPM) Max.. 51 (I scored 43)
CO % Max....... 0.48 (I scored 0.17)
NO (PPM) Max.. 419 (I scored 1247)
25 mph @ 1296 RPM
MAES %CO2.... 13.5
MAES %O2...... 1.9
HC (PPM) Max.. 35 (I scored 18)
CO % Max....... 0.46 (I scored 0.04)
NO (PPM) Max.. 709 (I scored 785)
My NO (PPM) numbers are what is failing my tests. Can anybody give me any ideas why this is happening? Again, any information will be geatly appreciated.
I went to get the somg test and came up with these numbers
15 mph @ 1971 RPM
MAES %CO2.... 12.9
MAES %O2...... 2.3
HC (PPM) Max.. 51 (I scored 57)
CO % Max....... 0.48 (I scored 0.42)
NO (PPM) Max.. 419 (I scored 843)
25 mph @ 1778 RPM
MAES %CO2.... 13.1
MAES %O2...... 1.9
HC (PPM) Max.. 35 (I scored 58)
CO % Max....... 0.46 (I scored 0.51)
NO (PPM) Max.. 709 (I scored 884)
Needless to say I failed. I welded 2 new cats and I passed everything except the "NO (PPM)." These were the scores I received the second time around...
15 mph @ 1318 RPM
MAES %CO2.... 13.1
MAES %O2...... 2.2
HC (PPM) Max.. 51 (I scored 43)
CO % Max....... 0.48 (I scored 0.17)
NO (PPM) Max.. 419 (I scored 1247)
25 mph @ 1296 RPM
MAES %CO2.... 13.5
MAES %O2...... 1.9
HC (PPM) Max.. 35 (I scored 18)
CO % Max....... 0.46 (I scored 0.04)
NO (PPM) Max.. 709 (I scored 785)
My NO (PPM) numbers are what is failing my tests. Can anybody give me any ideas why this is happening? Again, any information will be geatly appreciated.
03-03-2009, 02:28 AM
#2
Is this an EGR equipped car?
If so, check to see that it is working properly. Blockages, solenoids, etc.
High NOx is due to excessive combustion temps.
A mixture that is too lean or too much timing cause it also.
The EGR is used to lower NOx by reintroducing exhaust gasses back into the combustion chamber to help lower combustion temps.
Also, preignition can cause it too. Hot spots from carbon buildup in the combustion chamber can preignite the mixture resulting in high NOx.
If so, check to see that it is working properly. Blockages, solenoids, etc.
High NOx is due to excessive combustion temps.
A mixture that is too lean or too much timing cause it also.
The EGR is used to lower NOx by reintroducing exhaust gasses back into the combustion chamber to help lower combustion temps.
Also, preignition can cause it too. Hot spots from carbon buildup in the combustion chamber can preignite the mixture resulting in high NOx.
03-03-2009, 11:06 AM
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looks like your EGR is not functioning properly with Dan said. If needed I have my complete and working EGR setup for sale, i'll do $15 plus shipping if you need it..PM me if interested and i'll get it out asap for you..i'll get pictures today as well.
