Need emissions help, Colorado changing rules for v8 swaps

[Docwyte]

Thanks. I just did some research on it myself. Came across the cvn and checksum numbers. Looks like if you know what your doing you can change both numbers to whatever you want. I'm a amateur tuner so it was a little above my head. I'm really not sure why aftermarket tunes are a concern if if the car has to get exhaust gasses tested every year. I do know enough too that factory tunes are not the most efficient or pollution free tune. In addition it makes no sense if for example I want to bump up the pump pressure in my transmission so the clutches wear out slower and fail me for emissions in doing so.

I'm not sure that you can change the check sums/cvn's on a tune back to what they are stock. Tunes have been smog illegal for decades now, federal law says you can't change the software from what the manufacturer has it. It's just that it was never enforced at all until everyone and their brother decided to remove their catalytic convertors (even tho removing them adds no power) and also roll coal.

That drew the stink eye of the EPA and now the regulations are being enforced.

 

[White Stripe]

I'm not sure that you can change the check sums/cvn's on a tune back to what they are stock. Tunes have been smog illegal for decades now, federal law says you can't change the software from what the manufacturer has it. It's just that it was never enforced at all until everyone and their brother decided to remove their catalytic convertors (even tho removing them adds no power) and also roll coal.

That drew the stink eye of the EPA and now the regulations are being enforced.

I've not found much on exact federal laws and ecu tuning unless it's to defeat emissions. If no ecu tuning at all is allowed then I'm not sure how the thousands of tuning shops across the nation are allowed to be in business. Just in Denver alone there are a ton of tuning shops.

 

[J1000]

Checksum is adding up all the lines of code on the ECU and seeing what the number is at the end, so if you switch even one variable it changes the checksum. At least that's how I understand it.

I've not found much on exact federal laws and ecu tuning unless it's to defeat emissions. If no ecu tuning at all is allowed then I'm not sure how the thousands of tuning shops across the nation are allowed to be in business. Just in Denver alone there are a ton of tuning shops.

Any modifications to emissions system is illegal. Shops are able to do it because enforcement is done by states, not the feds. Also there is a grey area around race cars that provides justification.

Your suspicion is well placed however. I had my car dyno tuned a couple years ago and the owner told me he gets weird calls from blocked numbers asking him questions like "will you remove my catalytic converter?" Or "what's involved in your tuning process, how does it affect emissions?" Other people in the business get those calls too, he thinks it's state officials or investigators trying to understand how the industry works so they can attack it effectively.

He just tells them to make an appointment and doesn't answer questions like that on the phone.

Also the new EPA leadership is trying to outlaw race cars and/or require race cars to have all their original emissions equipment.

In response the industry has pushed the RPM Act forward which would protect motorsports: https://www.sema.org/epa-news

 

[Docwyte]

The reason why the EPA wants race cars to have their emissions intact is that for many, many years tuning parts were sold with the proviso "for off road use only". Then everyone was using them on their street cars....

 

[J1000]

Not just about limiting people's mobility, it's about limiting people period. Politicians and many in the elite rich class make no bones about the fact that they want to reduce the world's population drastically.

 

[White Stripe]

Checksum is adding up all the lines of code on the ECU and seeing what the number is at the end, so if you switch even one variable it changes the checksum. At least that's how I understand it.


Any modifications to emissions system is illegal. Shops are able to do it because enforcement is done by states, not the feds. Also there is a grey area around race cars that provides justification.

Your suspicion is well placed however. I had my car dyno tuned a couple years ago and the owner told me he gets weird calls from blocked numbers asking him questions like "will you remove my catalytic converter?" Or "what's involved in your tuning process, how does it affect emissions?" Other people in the business get those calls too, he thinks it's state officials or investigators trying to understand how the industry works so they can attack it effectively.

He just tells them to make an appointment and doesn't answer questions like that on the phone.

Also the new EPA leadership is trying to outlaw race cars and/or require race cars to have all their original emissions equipment.

In response the industry has pushed the RPM Act forward which would protect motorsports: https://www.sema.org/epa-news

I understand changing emissions is illegal on a federal level. But is reprogramming a ecu illegal on a federal level if emissions are left intact and operable? That's 2 different things. For example in an ecu you can program how long the daytime running lights or dome lights stay on after you shut off the vehicle, or adjust electric fan settings, or adjust fuel and spark tables. Is that illegal federally? We would make some adjustments at the dealerships for people based on personal preferences.
As far as shops, every tuner shop is changing fuel and spark tables. This can be done while keeping the emissions components operable. And the way obd2 emissions work, if left operable a modified tune will pass a gas analyzer test for federal emissions standard limits either stationary or on the chassis dyno unless the tune is really bad. However if the tune is bad the check engine light will come on or the monitors will never set. So-not talking about shops disabling emissions-if tuning at all is illegal, why are they allowed to be open?

 

[J1000]

I understand changing emissions is illegal on a federal level. But is reprogramming a ecu illegal on a federal level if emissions are left intact and operable? That's 2 different things. For example in an ecu you can program how long the daytime running lights or dome lights stay on after you shut off the vehicle, or adjust electric fan settings, or adjust fuel and spark tables. Is that illegal federally? We would make some adjustments at the dealerships for people based on personal preferences.
As far as shops, every tuner shop is changing fuel and spark tables. This can be done while keeping the emissions components operable. And the way obd2 emissions work, if left operable a modified tune will pass a gas analyzer test for federal emissions standard limits either stationary or on the chassis dyno unless the tune is really bad. However if the tune is bad the check engine light will come on or the monitors will never set. So-not talking about shops disabling emissions-if tuning at all is illegal, why are they allowed to be open?

The ECU is classified is an 'emissions device' so it cannot be messed with. Headlight timers or other things are controlled by a different computer, BCM, body control module, or other names. CARB certified tunes provide a way to adjust shift points, firmness, and can allow a higher RPM and things like that but at least on the cars I've worked on with CARB tunes the timing and fuel tables were not adjusted and locked out (Hondata and Diablo).

I know exactly what you are talking about, my tuned cars always passed the rolling road sniffer test with no problem. Always had cats and kept things like EGR. It always passed in CO until last year.

And technically race cars should not have their emissions equipment removed, neither shall farm vehicles or things like that. The way the law is written specifically says emissions equipment can not be modified nor removed after manufacture period. I believe the RPM Act or something like it will be passed to protect racing but then the hammer will just come down harder on street driven vehicles.

 

[Docwyte]

Because all the tuning was done on "off road vehicles" only. Wink, wink. There's also the issue of nowhere near enough enforcement of it. There is a way for tuners to do it legally, they need to submit their tunes for CARB certification.

Again, all this scrutiny we're now under (enforcing existing laws) is because people kept removing their cats, egr's, dpf's, rolling coal, etc, etc.

 

[rushthezeppelin]

Because all the tuning was done on "off road vehicles" only. Wink, wink. There's also the issue of nowhere near enough enforcement of it. There is a way for tuners to do it legally, they need to submit their tunes for CARB certification.

Again, all this scrutiny we're now under (enforcing existing laws) is because people kept removing their cats, egr's, dpf's, rolling coal, etc, etc.

Discounting the guys rolling coal (I think they are universally hated) the exhaust deletes that truckers were doing were because the emissions systems on new diesels are absolutely terrible and make engines much much less reliable.

 

[Docwyte]

Discounting the guys rolling coal (I think they are universally hated) the exhaust deletes that truckers were doing were because the emissions systems on new diesels are absolutely terrible and make engines much much less reliable.

That doesn't matter. They were removing emissions equipment and that's blatantly illegal.

 

[rushthezeppelin]

That doesn't matter. They were removing emissions equipment and that's blatantly illegal.

It doesn't matter that small companies with small fleets would sometimes have half their fleet down due to issues caused by the emissions systems? Seems like a pretty big deal to me and can be disastrous if you are an owner operator.

 

[nuclearlemon]

It doesn't matter that small companies with small fleets would sometimes have half their fleet down due to issues caused by the emissions systems? Seems like a pretty big deal to me and can be disastrous if you are an owner operator.

It is disasterous. unfortunately doesn't make it any less illegal. vote out those who enforce this if that's your choice, or take care of the old stuff and keep it on the road. when scamdemic parts shortages hit, owner/ops were digging all the 80s and 90s rigs out of fields and bandaiding them to get them back on the road.

 

[DaveInDenver]

I understand changing emissions is illegal on a federal level. But is reprogramming a ecu illegal on a federal level if emissions are left intact and operable? That's 2 different things. For example in an ecu you can program how long the daytime running lights or dome lights stay on after you shut off the vehicle, or adjust electric fan settings, or adjust fuel and spark tables. Is that illegal federally? We would make some adjustments at the dealerships for people based on personal preferences.
As far as shops, every tuner shop is changing fuel and spark tables. This can be done while keeping the emissions components operable. And the way obd2 emissions work, if left operable a modified tune will pass a gas analyzer test for federal emissions standard limits either stationary or on the chassis dyno unless the tune is really bad. However if the tune is bad the check engine light will come on or the monitors will never set. So-not talking about shops disabling emissions-if tuning at all is illegal, why are they allowed to be open?

You're lumping functional code with parameters. A checksum can be the whole memory or just a defined subset of memory. In this case the number they use would not include variables expected to change. There's legitimate values that you'd need to ignore, the air pressure, temperature, whatever otherwise every single checksum would be different on each car as it's operated. The fuel/spark map would be fixed algorithmically, so changing that would be inclusive to the checksum. It would not be a simple set of numbers per se, but the formulas would not be expected to vary. I have always thought using a checksum or firmware validation is a silly way to regulate this. Just set a tailpipe requirement and you either pass or fail it. It doesn't matter what's under the hood in the end.

 

[maxpowerzz]

Getting banana quotes for cats. Since I'm a 1988 can I just register it as an antique vehicle if I keep the annual mileage under 4,500? Am I correct that it no longer needs to pass emissions if an antique?

 

[Docwyte]

Getting banana quotes for cats. Since I'm a 1988 can I just register it as an antique vehicle if I keep the annual mileage under 4,500? Am I correct that it no longer needs to pass emissions if an antique?

Not really. For classic plates (vehicle is 25+ years old) you need to pass emissions every 5 years. So you need to pass emissions the first time you get them, then every 5 years after that

 

[nuclearlemon]

Since I'm a 1988 can I just register it as an antique vehicle if I keep the annual mileage under 4,500? Am I correct that it no longer needs to pass emissions if an antique?

Welcome to changing legislation. that's how it used to be way back in the day, but it changed a while ago to force those that were born emission compliant to still have to pass emissions.

 

[Stuckinthe80s]

Getting banana quotes for cats. Since I'm a 1988 can I just register it as an antique vehicle if I keep the annual mileage under 4,500? Am I correct that it no longer needs to pass emissions if an antique?

The only way to forgo the emissions is if it is a model year older than 1976 AND you register it as a classic, keeping it under 4,500 miles/year. That second part wasn't enforced when I registered my 1970 C10: nobody ever looked at my mileage and they even put "EXEMPT" in the mileage section of the title. When I go to renew my tags in 2026, it will be interesting to see if they record my mileage then.

 

[White Stripe]

Got a friend with a ls1 and a custom tune in his gm car. It just passed emissions with no issues. So maybe they are just picking on swaps with tunes.

 

[satchel]

It's not the emissions location that will test and fail you for a non stock tune. You get failed when doing a swap and are sent to the inspector to make sure the swap was done correctly, prior to being able to get the emissions done.

Got a friend with a ls1 and a custom tune in his gm car. It just passed emissions with no issues. So maybe they are just picking on swaps with tunes.

 

[Docwyte]

Tunes for VW/Audis/Subarus are getting found and those guys are getting failed unless they revert to a stock tune. That means it's going to roll downhill for the rest of the cars that have tunes on them, and those won't pass smog unless they have a stock tune. If the tune has a CARB EO#, then you take the car to the referee station and they inspect it and then annote the VIN with the tune infomation, then you go to Air Care and get tested.

Engine swaps are an entirely different beast, you're supposed to take them to the referee station so they can inspect it and make sure you've got all the necessary emissions stuff installed and it's all working. Then they annote their system with the VIN# and how it should be tested. Then you go to Air Care and they test it.