General Motors will recall 2001 through 2014 model-year Chevrolet Express CNG and GMC Savana CNG natural-gas vans due to a fire risk.

The recall will address faulty regulators in roughly 3,200 vans, which could cause the compressed natural gas (CNG) used to power the vehicles to leak out.

This is GM's second recall for leaking natural gas since last year, according to The Detroit News.

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The gas can cause a fire or explosion if exposed to an ignition source after leaking into the atmosphere.

Consequently, GM is telling owners not to start the engine or drive if they suspect that there is a leak. The company is not aware of any fires, crashes, or injuries related to this issue.

GM says replacement parts are on order, and customers will be notified by mail when they become available.

Dealers will then replace the regulator free of charge.

The recall will include 3,196 Chevrolet Express CNG and GMC Savana CNG vans from model years 2011 through 2014 sold in the U.S., as well as 13 in Canada.

GM reportedly became aware of the problem back in March, when a fleet customer reported the replacement of a CNG regulator in one of its vehicles.

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Engineers initially attributed the problem to another recall from May 2013, which fixed a problematic solenoid on the regulator.

However, analysis by GM and Impco--which supplies parts for the vans' CNG fuel system--found several cases of leaks that couldn't be attributed to solenoid replacement.

Those leaks were reportedly caused by flaws in the regulator itself, leading GM to begin this new recall.

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