Mark Chernoby, FCA's chief technical compliance officer, said during a conference call last week that FCA alerted the EPA to the problem after discovering it during routine in-use testing required by federal regulations on vehicles as they age.
Mayne said engineers discovered that sulfur in gasoline affected the washcoat inside the catalytic converter and caused it to fail. The washcoat is where chemical reactions take place to reduce emissions of carbon dioxide and other gases.
While an emissions-related recall may not motivate consumers to seek repairs the way a safety recall would, Chernoby said he isn't concerned.
"If these would've been 1990 vintage issue vehicles, I would've said we may have to try quite hard to get them back," Chernoby said on the call. "But this age of vehicle, I expect a pretty good response rate based on history."
Chernoby said FCA has devised a "recall playbook" over the years. He says the playbook calls for mailers to be sent to owners in the first outreach stage. Then, depending on success, the company could change course.
"If we don't see the type of response rate we would historically expect or want, we might move on to other activities [such as] social media, etc.," he said. "It's similar to what you see other OEMs doing."
FCA began sending mailers regarding the emissions recall last month, Mayne said.
FCA has a history of tangles with federal regulators over the timeliness and effectiveness of its safety recall notifications. In 2015, the automaker reached a consent decree with NHTSA, the nation's top safety regulator, calling for stricter policies that were to be model for the industry.