Your Toyota Camry DOES have adjustable timing. The ignition timing on your
1992 Toyota Camry CAN be adjusted. The mechanic is making a mistake, and the
smog technician may be correct as far as your Toyota's timing being off if
they checked the timing properly (by installing a jumper wire between timing
check connector terminals T & E).
Assuming the smog technician checked your Toyota Camry's timing properly,
then yes, your Camry does have a timing problem and the first step of the
diagnosis should be to set the ignition timing properly and retest your car.
Fixing the timing may very well lower CO and your 1992 Camry may pass the
smog check with the timing problem fixed.
If your car still fails the smog test after the timing correction you'll
need to begin the real diagnosis then. You will have a whole new set of
emission results to diagnose with. CO will no longer be .80 due to timing
adjustment. It may be higher, but more then likely lower.
CO stands for Carbon Monoxide. It is a by-product of incomplete combustion,
more then often related to the presentation of too much fuel to the
combustion chambers, or incorrect ignition timing. The spark created at the
sparkplug can only burn a small amount of fuel, the fuel it cannot burn is
sent out the tailpipe and will normally contain high levels of partially
burned fuel (CO) and un-burned fuel (HC). When timing is off and the spark
plug fires at the wrong time higher levels of CO are created.