Converting from CNG to gasoline?

Pretty straight forward.

Can I convert a vehicle that is CNG (and has probably always been CNG) to run on gasoline? (fwiw odometer is around 25K)
Is it expensive?
If so, who does that kind of work?
Is this a bad idea?

As I recall, converting a gas-powered vehicle to CNG involved a different tank, fuel lines and fuel injectors, so converting CNG to gasoline should go the other way. One thing I don’t know is whether conversion involves reprogramming the engine computer, so I wouldn’t trust it to a garden-variety mechanic. I do know some modifers offered bi-fuel kits so vehicles could run on either CNG or gasoline, so there shouldn’t be any substantial conversion problems.

Here’s a list of companies that make gas to CNG kits. Maybe one of them can put you in touch with a mechanic in your area who’s familiar with conversions, and who can advise you further.

I don’t really see why you would want to. CNG vehicles should hold their value a little better than a ho-hum gasoline version, and I’m not aware of any cars that are avaliable on CNG but not gasoline (unless this is a forklift or something). So it’d make more sense to sell your CNG vehicle and just buy a gasoline-powered one instead of spending a bunch of money de-converting it. I don’t even know if it’s possible on a modern car like the Civic GX.

I am assuming this is a newer vehicle since you said it only has 25k. If this were an older non fuel injected car or truck, the CNG conversions were a lot simpler and so would undoing one. And if this is some sort of oddball grey-market utility vehicle or something like that, you’ll probably have to elaborate a little more on what you’ve got.

This is a service van. It has been owned by the guvment. While it’s 8 years old, it’s seen little mileage. I would guess its been CNG since day 1.

But, given the scarce infrastructure for CNG, I’m only interested if I can convert to gasoline.

ETA :It’s a Chevy Express cargo van G2500 (3/4 ton), a 2002 IIRC

It’s possible the EPA will consider such a conversion “tampering with a federally approved emission control system,” which means you wouldn’t find a qualified shop willing to do it, just like you won’t find a reputable mechanic who will remove your catalytic converter.

And how would that differ from the original conversion from gasoline to CNG?

ETA: I am not buying this vehicle until I know for certain that it can be done and for how much.

Agreed…but note that the storage tanks may not have replaced the gas tank, and the lines and injectors could be compatible with gasoline (meaning the originals just weren’t compatible with CNG – kinda like replacing your gasoline-powered car’s fuel lines to run ethanol…they will then work with both). The bi-fuel thing shows you that a lot of the components should work for both CHG and gasoline. If you can find a mechanic and the parts, it might be just as simple to just add the bi-fuel kit to your CNG vehicle…I’m guessing it would be just as cheap and easy, and you’d retain the CNG setup, which might be nice if you can find a local station where you can fill up (and save money) and might help with resale value.

Here are some forums where you can ask people who REALLY know what they are talking about regarding CNG conversions…they can probably point you in the right direction regarding cost, a shop that can do the work, etc.

cngchat.com
cngforum.com

It might be faster and cheaper to convert it from CNG to LPG (propane) which is readly avalable.

I bought a been 2010 Ford Econoline cargo which used to be CNG I converted back to gasoline, I went to the junkyard and found fuel lines gas tank and injectors from another vehicle identical, what I needed to do was remove all the CNG tanks( be careful because those tanks are very heavy almost 300 pounds) for this particular car, You will also need to get a canister for fuel emissions system, After everything is installed do you have to call someone who program your car PCM engine computer back to original settings and everything will work as it came out a factory, I also have some pictures I can upload by the system is not letting me for now because I’m a new member…

Thanks for joining us. The person asking for advice was way back in 2010. I bet he never bought that van and his interest in CNG-gasoline conversions is long gone by now.

We talk about all sorts of things around here, sometimes including cars. You might enjoy hanging around.

I’m looking to do the same thing, except I’m not converting back. I’d just be making the conversion from CNG to regular gasoline (and in case anyone wonders, there are no CNG fill stations anywhere around where I want to go, like Eastern Washington, Montana, Northern Wyoming, and South Dakota). I’m curious because you said after doing all the replacements, you just need someone to reset your computer back to original settings. Do you know if this would be a problem since I think it came as a natural gas setup, or is their still a relatively painless way to get the PCM set right?

Thanks for all the info you offered. Helps a lot.

I have the same question! I have two Honda Civic CNG vehicles I bought at auction, very low miles, and driving to a fill station takes half a tank–and the tanks are expired anyway. These vehicles were not converted, they were made for CNG from the factory but I want nothing to do with CNG anymore. (I saw the comment about messing with a federal emissions system, and as a lawyer, I don’t care about that argument. As long as I meet current emission standards, I’m fine!). I can do it all myself, except–I can’t reprogram a PCM if that will be required. So I’m looking for the same info. Please answer this question as I’m sure there are lots of people with expired tanks and/or they are tired of CNG for other reasons. Thanks,