The thermostat may fail to close completely, causing the Check Engine Light to illuminate. This problem will prevent the engine from reaching normal operating temperature; a new thermostat should be installed.
Car Problem Reports
Dodge Magnum Check Engine Light Due to Failed Thermostat
Dodge Magnum Problem
Engine Affected: 5.7L V8 HEMI
Average Mileage: 87,745 mi (45,000 mi - 142,000 mi)
Visitor, 2005 Dodge Magnum, 5.7L V8 HEMI, 45,000 mi
check enigine light came on do to bad thermostat