CTV News has learned that of the 1.6 million Ontario Drive Clean On-Board Diagnostic tests done this year, the initial failure rate has risen from 5 per cent in 2012 to 8 per cent this year, after changes to the system used for testing vehicles.

About 128,000 cars failed the test this year, after a switch to computerized testing for newer model vehicles. Once they fail, the owner has to pay for a second test.

While older vehicles built in 2006 and earlier are still tested with a two-speed tailpipe test,newer model cars are tested using the vehicle’s computer, which according to the Drive Clean website: “takes advantage of the computerized monitoring equipment in today’s technologically advanced vehicles.”

Many of the cars that are failing the new on-board diagnostics (OBD) aren't even bad polluters. Many simply fail because the battery in the car had previously died, or there's a glitch in the car's computer, but those people still have to pay for a second test after having the issue diagnosed.

Ontario Drive Clean was set up to ensure that vehicles meet the province’s fuel emissions standards. While the program was not intended to make money, it has –- with a running total of $19 million in profits for the province’s coffers.

CTV News has learned that the Liberal government is considering cutting the Drive Clean fees to ensure the program stops making profits.

The $35 test is mandatory for cars seven years or older, and necessary for vehicle license renewal. The testing is done at more than 2,000 testing stations across the province.

Environment Minister Jim Bradley defended the testing program and said it protects Ontarians from smog or emissions. He says the rise in fail rates is due to better detection.

"When you have a new program that's more accurate, more up to date with new equipment, they're bound to find problems that couldn't be detected by a previous test,” Bradley said.

Peter Tabuns, the NDP critic for energy, says Ontario should be checking the equipment and ensure that people don’t have to have repeat tests unnecessarily. The Conservative critic, Michael Harris, calls the program a "cash grab."

CTV News has also learned that the new testing method for older vehicles is allowing more of the old clunkers to pass. In 2012, 18.2 per cent of older vehicles failed the emissions test. This year, only 8 per cent are failing.

In 2013, 10 per cent of vehicles registered to Drive Clean program are model year 1988-1997.