The turbocharged, 1.5-liter four-cylinder engine found in Honda’s CR-V and Civic models, two of America’s best-selling cars, has a fuel leakage problem, according to industry watchdog Consumer Reports. The Japanese automaker has quietly extended the powertrain warranty of over one million cars to reassure owners that they won’t need to cover an expensive repair bill if they encounter a mechanical problem.

The issue is seemingly limited to CR-Vs made during the 2017 and 2018 model years, and Civics manufactured between the 2016 and 2018 model years. Consumer Reports published a memo Honda sent to its American dealers that blames the problem on software settings or hardware failures, without providing additional information. Owners of affected cars will be able to tell that they have a problem right away; the defect causes cars to misfire, lose power, and run more loudly than usual. It might trigger a check engine light, and some owners have even complained that their car stalled, which can lead to a hazardous situation. The last thing you want is your car turning off when you’re turning left across a busy road.

While Honda announced that motorists in cold-weather states were much more likely to experience this problem, Civic and CR-V owners in warm-weather states like Texas and California told Consumer Reports that they’ve encountered the issue during the hot summer months. Honda hasn’t revealed how many cars are affected by the defect, though nearly 240,000 cars were eligible to receive new software developed in 2018 to fix the problem.

Honda has refused to issue an official recall in the United States. In China, it recalled hundreds of thousands of cars to fix a similar problem in 2018.

To win back the trust of consumers, Honda is extending the powertrain warranty of 1.5-liter-powered CR-Vs and Civics made during the aforementioned model years by one year. They’re now covered for six years from the time of purchase. There is no mileage limit. Honda will notify eligible owners in the coming weeks.

“Abnormal oil dilution remains extremely rare, especially outside of extremely cold weather. In extreme and rare cases in the cold-weather states, where abnormal oil dilution has occurred prior to a vehicle receiving the software updates, this extension will provide extra time for any undetected engine damage to become apparent and be covered by the warranty,” Honda spokesman Chris Martin told Consumer Reports.

If you own a 2017 or 2018 Honda CR-V, watch for any indications of problems with the oil system, including oil indicator lights or the smell of gasoline inside the vehicle. If you have any issues, take your car to a Honda dealer to have it checked. Also, Consumer Reports suggests that if you have problems to report them to Honda and the National Highway Traffic Safety Administration. To date, the NHTSA has not issued a recall.

Updated on May 28, 2019: Added information about the warranty extension.