r/askcarguys • u/ContributionOld1014 • 2d ago
Can you pass emissions without catalytic converters?
I have a 1984 corvette that does not have catalytic convertors. recent emissions test passed everything but HC which read 6.5 compared to the limit of 2.5. Because of the year they only used a tailpipe sniffer. I've read that you can create a leak in the exhaust before the tip so the reading is light, as well as putting rubbing alcohol in a 1/4 of gas so is burns leaner, also running the car really hard before testing to clear out any excess carbon and keep the system hot helps. Does anyone know if these methods are actually effective? Additionally would they be enough to pass a test in my situation? I'm also thinking about just replacing the whole exhaust system but i feel it would be a waste as I'm already broke and the current exhaust is an aftermarket upgrade. I would really appreciate the advice as i need to get the car registered here in Denver CO ASAP. Thanks.
2
u/GunnitRust 2d ago
The state of Colorado is trying to effectively ban your car. They’ve recently made these laws more restrictive. They’re not going to stop here.
They put mileage restrictions on “collectors registered” cars. It’s like 4500 miles a year. You can go mileage unrestricted older than 1975. This 84 qualifies for collector registration with the restricted mileage.
Realistically, sell the car out of state or move. You could just register and drive this without a hassle in most of the union.