1HD-FTE Diesel Swap LX450, Impossible to Register due to Colorado Emissions Program.

[Mag71k5]

Hey all, I've been working up to take the FTE, LX450 for emissions.

If you live in the Colorado Metro areas, odds are you'll have to take your vehicle for emissions testing before you can register, and plate/tag the vehicle.


As the title states, I am now stuck in legal limbo with my LX450. I'll give a brief history of my total registration/title history in case this may help others who are thinking of doing the swap in the area where emissions are required.

• Early 2025 - When I bought the LX450 both cats were removed, so at the time I opted to just pay sales tax in Jefferson County, CO. This allowed me to get a temp tag, and gave me time to find some catalytic converters for emissions.
• April 2025 - I decided to go down the diesel rabbit hole, and found about the 1hdfte, I then bought an HDJ100, getting me my engine. I had also moved to a new County, this complicates things further, Jefferson County took the tax money, Adams county wanted to charge that same tax again to continue registration, I didn't follow through because taxation is theft, and I had already paid a sales tax, to the same state.
• September 2025 - The swap is complete, and now I need to register this thing and get an actual plate instead of temp tags that are only good till OCT 10, 2025.
• Oct 2025 - To register a diesel, the tag office states you need to get a vin verification/road worthy inspection done by Colorado State Patrol, easy enough.
  -DR 2704, Is filled out by the State Patrol, they check safety equipment, lights, horn, brake switch.
  -They also State, "Vehicle converted from Gas to Diesel"
• Feb 2026 - To be able to emissions test a "grey" market vehicle/engine, you need form DR 2365 filled out by a technician/supervisor at the Denver Emissions Technical Center, my understanding is they somehow, try to confirm if your engine/vehicle has its emissions equipment, and it's still installed/operational.
  
  Now I didn't have high expectations for passing this because I've deleted the crossover/EGR, but I held onto it in the event I needed it to pass emissions. The impossible part with this is, and as I understand it from the supervisor. The Emissions Technical Center or EPA, have zero frame of reference for the engine, or the emissions equipment it's supposed to have. I argued why should they care for a frame of reference when the vehicle the engine is in, the vehicle that was imported, and the engine are all 25+ years or older? He stated they are still required to be certified by the EPA to be tested and registered in the Emissions Program Area. I also argued I could provide parts diagrams showing what these vehicles came with in stock form regarding emissions equipment. He stated that's not enough, and the burden is on ME to find a vehicle that was sold in the united states with the same engine that I've swapped into my LX450... Which we all know here, doesn't fucking exist. He was nice enough to recommend a Cummins 2.8 repower
  
  Here's the killer for guys trying to swap, the supervisor has basically stated, if you swap a grey market diesel engine, into any vehicle. They WILL not allow you to get an opacity test at an emissions shop, basically killing the pathway to legally register your vehicle in the state of Colorado. He also stated, that the vehicle is technically illegally operating on Colorado roads.
  
  I know there are other methods, Registering outside of the Emissions program requires a proof of residence, which I do not have. The Montana LLC route, which I fear is a ticking timebomb because some states may view it as tax evasion.
  
  I could attempt to register it in two other states we own property in, Georgia, or Oregon. Which basically puts me in the Montana plate category. I'm going to ponder on it and think next steps.
  
  Anyway, if you live in an emissions enforcing area hellscape, move. I would, but I just bought a house, and I really like my garage.

 

[Doughboy]

Hey all, I've been working up to take the FTE, LX450 for emissions.

If you live in the Colorado Metro areas, odds are you'll have to take your vehicle for emissions testing before you can register, and plate/tag the vehicle.


As the title states, I am now stuck in legal limbo with my LX450. I'll give a brief history of my total registration/title history in case this may help others who are thinking of doing the swap in the area where emissions are required.

• Early 2025 - When I bought the LX450 both cats we're removed, so at the time I opted to just pay sales tax in Jefferson County, CO. This allowed me to get a temp tag, and gave me time to find some catalytic converters for emissions.
• April 2025 - I decided to go down the diesel rabbit hole, and found about the 1hdfte, I then bought an HDJ100, getting me my engine. I had also moved to a new County, this complicates things further, Jefferson County took the tax money, Adams county wanted to charge that same tax again to continue registration, I didn't follow through because taxation is theft, and I had already paid a sales tax, to the same state.
• September 2025 - The swap is complete, and now I need to register this thing and get an actual plate instead of temp tags that are only good till OCT 10, 2025.
• Oct 2025 - To register a diesel, the tag office states you need to get a vin verification/road worthy inspection done by Colorado State Patrol, easy enough.
  -DR 2704, Is filled out by the State Patrol, they check safety equipment, lights, horn, brake switch.
  -They also State, "Vehicle converted from Gas to Diesel"
• Feb 2026 - To be able to emissions test a "grey" market vehicle/engine, you need form DR 2365 filled out by a technician/supervisor at the Denver Emissions Technical Center, my understanding is they somehow, try to confirm if your engine/vehicle has it's emissions equipment, and it's still installed/operational.
  
  Now I didn't have high expectations for passing this because I've deleted the crossover/EGR, but I held onto it in the event I needed it to pass emissions. The impossible part with this is, and as I understand it from the supervisor. The Emissions Technical Center or EPA, have zero frame of reference for the engine, or the emissions equipment it's supposed to have. I argued why should they care for a frame of reference when the vehicle the engine is in, the vehicle that was imported, and the engine are all 25+ years or older? He stated they are still required to be certified by the EPA to be tested and registered in the Emissions Program Area. I also argued I could provide parts diagrams showing what these vehicles came with in stock form regarding emissions equipment. He stated that's not enough, and the burden is on ME to find a vehicle that was sold in the united states with the same engine that I've swapped into my LX450... Which we all know here, doesn't fucking exist. He was nice enough to recommend a Cummins 2.8 repower
  
  Here's the killer for guys trying to swap, the supervisor has basically stated, if you swap a grey market diesel engine, into any vehicle. They WILL not allow you to get an opacity test at an emissions shop, basically killing the pathway to legally register your vehicle in the state of Colorado. He also stated, that the vehicle is technically illegally operating on Colorado roads.

Could you find a stock HDJ100 that had been registered in Colorado to use as a baseline or because it isn't a NAS truck, it doesn't count?

Colorado is odd with engine swaps, I haven't gone down the engine swap rabbit hole in a while, but I do remember that you can't swap in an older engine than whats coming out and to get it inspected (by the state I think, or authorize shop?) to make sure it was done correctly, had emissions equipment ect. That was years ago though. I have no clue what any of the laws are now.

I've gone through the process of registering a grey market vehicle a dozen times or so, gas and diesel, but never one with a swaped engine from a grey market vehicle.

When I just bought my HDJ81, it was originally put into the system as gas, and I didn't notice for 5 years or so, maybe 6 and I kept going to the diesel emissions place to get it smogged and on that 6th year the guy was like "hey man, it says its gas here and the vin doesn't match." So I had to go back and redo my inspection to get a proper DR 2365

The inspection place in Denver is wild. One guy is chill, the other is a prick and gods gift to inspections.

That sucks man, I wish I had some sort of guidance to give you.

 

[Doughboy]

Can you register it as a diesel on the title in say MT, OR whatever state. Then do a title transfer to Colorado and just do emissions at a diesel testing center? Then play dumb?

 

[Mag71k5]

Could you find a stock HDJ100 that had been registered in Colorado to use as a baseline or because it isn't a NAS truck, it doesn't count?

Colorado is odd with engine swaps, I haven't gone down the engine swap rabbit hole in a while, but I do remember that you can't swap in an older engine than whats coming out and to get it inspected (by the state I think, or authorize shop?) to make sure it was done correctly, had emissions equipment ect. That was years ago though. I have no clue what any of the laws are now.

I've gone through the process of registering a grey market vehicle a dozen times or so, gas and diesel, but never one with a swaped engine from a grey market vehicle.

When I just bought my HDJ81, it was originally put into the system as gas, and I didn't notice for 5 years or so, maybe 6 and I kept going to the diesel emissions place to get it smogged and on that 6th year the guy was like "hey man, it says its gas here and the vin doesn't match." So I had to go back and redo my inspection to get a proper DR 2365

The inspection place in Denver is wild. One guy is chill, the other is a prick and gods gift to inspections.

That sucks man, I wish I had some sort of guidance to give you.

The swap kills it apparently, he just kept saying, Engine must be same year models or newer AND be EPA certified.

Im just going to find a way out of the emissions area.

 

[unimogguy]

If you own property in GA just register/title it there and be done with it. Outside of the city of Atlanta I can’t imagine anywhere else in GA requiring emissions testing. If Atlanta even does?

 

[Mag71k5]

If you own property in GA just register/title it there and be done with it. Outside of the city of Atlanta I can’t imagine anywhere else in GA requiring emissions testing. If Atlanta even does?

Metro Atlanta does, my property is way up north bordering Tennessee, no emissions there.

Its definitely on the table.

 

[wesintl]

Dumb. So you can buy an import with that engine and get a form and drive it around but you can't swap the same engine because it's not epa or carb certified. Gonna have to register it outside of emissions counties or out of state.

Calirado at it's finest

 

[Mag71k5]

Dumb. So you can buy an import with that engine and get a form and drive it around but you can't swap the same engine because it's not epa or carb certified. Gonna have to register it outside of emissions counties or out of state.

Calirado at it's finest

Yeah, gotta protect the environment from the 12 diesel swapped gray market engines in the history of Colorado... Meanwhile we'll build 15 Data Centers that suck up our water and energy resources, so a 12 year old can cheat on his history homework and still fail.

 

[OilHammer]

Not to mention the swapped trucks probably don’t drive 10k/yr anyway. Makes me wonder how they handle a pure scratch built car now.

 

[OilHammer]

Here’s an idea. Swap in a Prius drivetrain and finish the registration as an electric. Once established, swap to diesel. . Might exempt you from emission testing ever again.

 

[Mag71k5]

Here’s an idea. Swap in a Prius drivetrain and finish the registration as an electric. Once established, swap to diesel. . Might exempt you from emission testing ever again.

I thought about putting the lx450 on a tesla chassis, with a cummins 6bt. Maybe I can register it easier that way.

 

[HDavis]

@Cruisertrash went down this rabbit hole when he was looking at 3b swapping his 60. He came to the same conclusion as you.
The 70 series conversions on 80 frames with diesels will suffer from the same challenges.

 

[Mag71k5]

@Cruisertrash went down this rabbit hole when he was looking at 3b swapping his 60. He came to the same conclusion as you.
The 70 series conversions on 80 frames with diesels will suffer from the same challenges.

Yup, Hopefully this helps people prepare for that. If you live in the emissions area, get ready to title and register it somewhere else.

 

[Cruisertrash]

@HDavis I would never 3B swap, don’t come at me like that … it was a 2H! Haha

Anyway, yeah, I ended up on the phone with the head guy in the state who runs the department overseeing emissions for petrol and diesel. Imports and engine swaps fall under his purview as well. Here’s what I learned:

1. Domestic engine swaps into a domestic vehicle is fine as long as the engine is the same year or newer and includes all factory emissions components for the engine.
2. IImported vehicles are fine as long as they abide by federal regs and have proper paperwork.
3. Swapping an imported motor into a domestic vehicle is (and I quote the guy) “not something I will ever sign off on.”

Note that I said the guy is the head of this department for the STATE. That means the rules apply not only in smog counties, but everywhere in Colorado. Now, non-smog counties don’t ever inspect your vehicle. So with that what you will.

 

[Mag71k5]

@HDavis I would never 3B swap, don’t come at me like that … it was a 2H! Haha

Anyway, yeah, I ended up on the phone with the head guy in the state who runs the department overseeing emissions for petrol and diesel. Imports and engine swaps fall under his purview as well. Here’s what I learned:

1. Domestic engine swaps into a domestic vehicle is fine as long as the engine is the same year or newer and includes all factory emissions components for the engine.
2. IImported vehicles are fine as long as they abide by federal regs and have proper paperwork.
3. Swapping an imported motor into a domestic vehicle is (and I quote the guy) “not something I will ever sign off on.”

Note that I said the guy is the head of this department for the STATE. That means the rules apply not only in smog counties, but everywhere in Colorado. Now, non-smog counties don’t ever inspect your vehicle. So with that what you will.

Yeah... I read through your thread. Smart on you doing research first lol.

Looks like my new LLC just acquired a LX450. Imagine that.

 

[LARGEONE]

Call Lee Zeldin and file a complaint

 

[Corbet]

I’d register at one of your other properties. Assuming there is a house on one the state would have a hard time arguing with you if there is another vehicle in your driveway with CO tags.

Otherwise vacant land is really cheap in the San Luis valley. But I don’t know what else you’d need to register there? Colorado is a tough state to build cool trucks in.

I’ll probably keep my life simple with the 40 build and just order a E-Rod LS from GM Performance as those even pass in CA.

 

[Lastresort576]

Yeah... I read through your thread. Smart on you doing research first lol.

Looks like my new LLC just acquired a LX450. Imagine that.

so did you go the montana route? im very tempted in going this route myself...for a newer M3..cuz yeah taxes. But im hesitant because i feel like it would be a nonstop hassle having out of state plates residing in state and the laws against doing so.

 

[Mag71k5]

so did you go the montana route? im very tempted in going this route myself...for a newer M3..cuz yeah taxes. But im hesitant because i feel like it would be a nonstop hassle having out of state plates residing in state and the laws against doing so.

Yes, I went that route. I may be an odd example though, because ive already paid sales tax on it when I attempted to title it.

The motor vehicle office charged me to title it, but then said my title was messed up from the dealer.

So the tax was paid, and associated fees but I never changed over the title.

So if I get pressured over taxes, I have that receipt.

 

[wesintl]

They don't pull people over for long over due expired tags but i'm sure they will target someone with a Ford GT or a LandCruiser because it has Montana plates...