One problem related to fuel injection rail has been reported for the 2004 Chevrolet Impala. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Chevrolet Impala based on all problems reported for the 2004 Impala.
2004 Chevrolet Impala, 3. 4l, 134,000 miles, fuel pressure regulator leak at cold (below freezing) start up. Leak was between the upper and lower stamped housing of the fuel pressure regulator canister. Leak was not at the regulator to fuel rail seal, or between the regulator to return line seal.