It passed! Let me give a little bit of background. It's a 1990 F250, it started out as a light duty F250, complete w/ a 302 and a Mazda 5 speed. It now has a 351, ZF-5 trans and 1 ton axles. I did the swap last year with only a few minor glitches. I have 'Historic' tags on the truck, in mary-land if a vehicle is 20 years old or older, it can run those tags w/ a few stipulations such as, it can't be used as a daily driver. It is safety inspection and emission exempt which worked well for me, the truck only gets used a few times a month at the most.

Fast forward to the present- I've been thinking very seriously about moving to Colorado. I know from friends that most vehicles there have an annual emission test. I wasn't sure if my truck would pass, so I took it to a test station ( in MD.) to do a voluntary test reasoning that if it passe here, it should pass in CO. The test facility uses a tail pipe sniffer, so I went through the drill and get handed the slip- it couldn't have been running any cleaner! The funny part about it is- the test station types in the VIN and it comes up w/ the test standards, so the test computer was testing for a 302, not the 351 that's in the truck. The 351 was running so clean it, it posted great results that the smaller engine should be putting out.

 

Why would you think it wouldn't pass? Do you not have a Cat, smog pump or the like emissions related items?

And it doesnt matter what engine is in the truck, the 300 6 and the 460 both have the same emissions standards to pass

 

All of the emission components are in place, but without a proper 'sniffer' test there was no way to know if they were actually working correctly.

 

In CO it depends on what county you live in. The Denver area has to get tested but here in Pueblo county it's not required, IIRC. I haven't gotten my rigs registered yet but that's what the DMV website said.

I used to live in eastern Oregon and they never checked anything out there. When you would first register a vehicle they would look at the VIN on the dash to make sure the paperwork was right. After that you just sent in $65 to renew the tags every two years.

 

Usually rural areas are emissions exempt, but large metro areas have tests.

 

True.

Mine runs like absolute dog crap and somehow it still passed here in CO.

Also, just an FYI, be prepared to pay through the nose for registration. CO loves to hit you up with a tax for new plates. You will also most likely be required to weigh your truck on the scale unless the title states the GVW and you will be required to have a VIN inspection performed before registering. If you plan to move to the Front Range, i.e. Kansas but called Colorado, go to Berkenkotter motors. They will do the VIN inspection for free.

 

I don't know how this actually works, but in pa my 90 passed awesomely as well because it looks as though it uses a multiplier to get total emissions allowed. So more displacement allows more pollutants, but the ratio of pollutant to displacement stays constant.
My truck didn't even use 15% of the allowed emissions.
I wasn't about to argue. I paid the bill and walked away.