My daughters 1996 328is just failed California smog check. Here are the numbers:
HC (PPM) NO (PPM)
MAX AVE MEAS MAX AVE MEAS
15 mph 54 9 78 430 67 446
25 mph 37 6 37 717 62 192
Basically failed at 15 mph for HC and NO. Going to start by changing out O2 sensors and plugs. Just changed oil a week ago. No CEL codes. Any other suggestions?