Tesoro Hawaii said it has been alerted to a possible contamination with the premium 92 octane gasoline sold at its Haleiwa station.

“We are aware that some customers’ vehicles have been impacted by this fuel and we are committed to addressing this issue,” Tesoro said in a statement today. “As a precaution, our store operators shut down the premium and midgrade gasoline pumps at that station. We believe this is an isolated incident, but a full investigation is under way to determine the exact cause.”

Tesoro said all fuel manufactured at its Kapolei refinery undergoes rigorous testing before being distributed.

“We have received no reports of fuel issues at our other retail gasoline locations in the state,” Tesoro said.

Tesoro is asking customers whose vehicles have been impacted by this incident to call (877) 876-5383, between the hours of 8 a.m. and 5 p.m.