Only 21 vehicles failed the emissions test last year following 12,529 reports on a dedicated text messaging number.
Three messages are required from three different phones before a vehicle is called for inspection. From these, 250 were called and 21 of them failed the test.
Answering a PQ by Opposition MP Marthese Portelli on Tuesday, Transport Minister Joe Mizzi explained that when a vehicle failed the test, the owner was fined and given another appointment.
The fines continued until the vehicle finally passed the test.
If the owner failed to keep two appointments, a note was entered that its licence could not be renewed. This was removed when the vehicle eventually passed.