Vehicle manufacturers have programmed the check engine light to illuminate only when there is a vehicle problem which might increase emissions. With that said, anytime the check engine light is on a vehicle will fail the smog test. You will need to have your 1999 Acura TL diagnosed by a certified smog check repair center, have the trouble codes retrieved, the faults corrected, and then obtain a smog test.
Although your Acura TL might not display symptoms of engine or drivetrain trouble, its computer system may be operating under preset (pre-programmed) settings in order to maintain as low emissions and high engine efficiency as possible. The fault(s) will need to be repaired for the computer to return to using real-time engine data in order to calculate best air/fuel ratio.
