Just an FYI for those interested in Emissions.
Took my '91 3.1L Pontiac Sunbird in for E-Test and it failed (first set results below). Thanks to various rec.autos.tech posts, the fix pointed to replacement of O2 sensor. I replaced O2 sensor, and all is well (passed with second set of results below).
Just thought I would post my failed and passed measurements as a guide to others.
FAILED Measurements: ASM 2525 CURB IDLE HC ppm 79 121 FAIL 200 197 PASS CO Percent 0.44 0.09 PASS 1 0.04 PASS NO ppm 908 473 PASS N/A N/A N/A
PASSED Measurements: ASM 2525 CURB IDLE HC ppm 79 68 PASS 200 143 PASS CO Percent 0.44 0.03 PASS 1 0.49 PASS NO ppm 908 635 PASS N/A N/A N/A