[s-cars] my '92 failed smog

[Theodore Chen]

here are the numbers:
idle (792 rpm) CO2 14.3% O2 0.70%, HC 211ppm (max 120) CO 0.11% (max 1.00)
2512 rpm CO2 14.4% O2 0.40% HC 68ppm (max 140) CO 0.32% (max 1.00)

there aren't any numbers here for NOx.

two years ago, it passed easily:
idle (1004 rpm) CO2 14.6% O2 0.5% HC 66ppm (max 120) CO 0.00% (max 1.00)
2550 rpm CO2 14.9% O2 0.0% HC 3ppm (max 140) CO 0.00% (max 1.00)

the turbo was changed during that time, to a GT2871 hybrid. however, the
software and injectors are the same as before, and so is the induction system
(still using stock airbox). i can't see that change causing the jump in HC.

any ideas?

i thought it might be the catalytic converter, but the O2 numbers seem pretty low.  doesn't seem like there's a lot of extra oxygen for the cat to use in converting the unburned HC.

-teddy