FORT COLLINS, Colo. (CBS4)- New emissions tests are underway and under attack in northern Colorado. Six Republican lawmakers are behind a bill that would exempt Larimer and Weld Counties from the tailpipe tests.

A bill introduced in the State House would put the brakes on new emissions tests in Larimer and Weld Counties.

"I am introducing the bill based on the record provided by the Department of Public Health and Environment that we are meeting the standards," said Rep. Glenn Vaad, (R) Mead.

Rep. Vaad said if northern Colorado is in compliance, why put drivers through the hassle of emissions testing and possibly expensive car repairs?

"My bill also allows the department or air quality commission to re-institute the emission exceptions program should we slip and go into sub-standard readings in Larimer and Weld Counties," said Vaad.

The Colorado Health Department said engine emissions in the northern part of the state can raise ozone levels in other parts of the Front Range, putting the state at risk for a tougher federal crackdown.

"I think the key is that some people think that pollutants have to affect you right where they're emitted," said Fort Collins Environmental Planner Brian Woodruff.

Woodruff said cars in Fort Collins need emissions standards because ozone pollution travels, and it's a regional problem.

"So to exempt one part of the region means that they wouldn't be doing their share of reducing emissions," Woodruff.

Drivers have mixed reactions to the new testing requirements.

"I don't think it should be done. It hasn't been done for years, so why start now? I think it's just a money maker," said Fort Collins driver Missie Anderson.

"Honestly, I don't have a problem with it as long as it's helping everything out with the community and whatnot," said Fort Collins driver Danny Pilkington.

If the bill passes, the emissions tests in northern Colorado would end July 1.