The 2000 Toyota Celica is not a "known" smog test problem vehicle. It seems as though this particular Toyota Celica might have not been receiving the correct repairs required to pass the smog inspection, instead simply being applied a "quick fix" to get it to pass the smog inspection.
In terms of if and what repairs might be needed during future smog inspection, is an unknown. This Toyota Celica could have failed its smog inspection for dozens of different reasons.
If you are serious about this vehicle it would be best to invest in a certified pre-inspection from a local Toyota dealership or certified Toyota expert. You will also want them to run a smog check pre-test in order to learn whether or not it will pass a smog check.
