The Cow Fire east of Millville was caused by hot pieces of metal spewed from the tailpipe of a car with a disintegrating catalytic convertor. That’s the determination Cal-Fire Investigators have made. A witness had seen a poorly running vehicle pass by just before the fire started, and the vehicle was found in Palo Cedro early Monday morning. The catalytic convertor was found to be failing. A lot of fires start this way, so it’s important for drivers to know the signs. The most obvious is by reading the code after a check engine light goes on. Symptoms include reduced power, especially on hills, and a misfiring engine. The Cow Fire started around 3:30PM Sunday afternoon off South Cow Creek Road and Highway 44. 18 homes had to be evacuated, but residents have been allowed to return home. Two minor structures were destroyed. One firefighter has been injured. The fire remains at 761 acres, now with 65% containment.