Failed smog, what to fix?
April 26, 2010 3:16 PM Subscribe
Hello AskMe Mechanics! My 1999 Chevy S-10 just failed its emissions test and I need some reliable information as to why and towards what I can do to make sure it passes next time.
posted by carsonb to Travel & Transportation (8 answers total) 1 user marked this as a favorite
The truck is relatively low-mileage: ~70,000mi.
It just had a fluids-change last week, but I probably need to change the air filter soon.
The test was conducted in Los Angeles, CA at a Test Only station (they didn't have the capacity to work on the truck) and measures a bunch of stuff at two different speeds: 15mph and 25mph. My truck passed every metric except the NO (PPM) at 15mph. At 25mph the NO measured very low at 35ppm, but at 15mph it was waaay over the max (533) at 843ppm.
Ray, the man with the machine, wasn't able to fathom why it would pass the 25mph test with flying colors but fail at 15mph.
Do you know why? And what should I ask the mechanic to do when I go to have it fixed?