I just went down to the TEST ONLY station for my Smog check and failed because the NOx was too high so now I am a GROSS POLLUTER.
Here are my numbers:
Timing = 12* (spec is 10*)
15 mph (1710 rpm)
CO2 - 13.8%
O2 - 0.9%
HC - 129ppm (127max / 314gp)
CO - 0.84% (0.78max / 2.08gp)
NO - 2601ppm (1031max / 1822gp) Gross polluter!!!!
25 mph (2629 rpm)
CO2 - 14.8%
O2 - 0.5%
HC - 56ppm (108max / 264gp)
CO - 0.46% (0.99max / 2.29gp)
NO - 721ppm (891max / 1622gp)
Downey headers, 10K miles on new motor with rebuilt heads, 100K on all other parts.
Everything that I have read points to the EGR system. I pulled the engine codes and came up with error code 71.
Error Code 71:
EGR gas temp sensor signal (THG) is below "A" after driving for 240 seconds in EGR operation range. "A" is THA + 30*C for California spec and THA is the air temp sensor in the air flow meter.
So, I was inspecting the EGR circuit and I noticed that I could not get high vacuum when I put manifold vacuum on port R of the vacuum modulator while at 3500 rpm. I believe this is a problem with the VSV???
What controls the VSV to turn on and off?
Any help is appreciated and I will add more info as I have time to check each circuit of the system.
Here are my numbers:
Timing = 12* (spec is 10*)
15 mph (1710 rpm)
CO2 - 13.8%
O2 - 0.9%
HC - 129ppm (127max / 314gp)
CO - 0.84% (0.78max / 2.08gp)
NO - 2601ppm (1031max / 1822gp) Gross polluter!!!!
25 mph (2629 rpm)
CO2 - 14.8%
O2 - 0.5%
HC - 56ppm (108max / 264gp)
CO - 0.46% (0.99max / 2.29gp)
NO - 721ppm (891max / 1622gp)
Downey headers, 10K miles on new motor with rebuilt heads, 100K on all other parts.
Everything that I have read points to the EGR system. I pulled the engine codes and came up with error code 71.
Error Code 71:
EGR gas temp sensor signal (THG) is below "A" after driving for 240 seconds in EGR operation range. "A" is THA + 30*C for California spec and THA is the air temp sensor in the air flow meter.
So, I was inspecting the EGR circuit and I noticed that I could not get high vacuum when I put manifold vacuum on port R of the vacuum modulator while at 3500 rpm. I believe this is a problem with the VSV???
What controls the VSV to turn on and off?
Any help is appreciated and I will add more info as I have time to check each circuit of the system.