# 2004 Chevrolet Impala - Problems, Statistics, and Analysis

## Common problems of the 2004 Chevrolet Impala

1,203 problems have been reported for the 2004 Chevrolet Impala.
The following chart shows the 24 most common problems for 2004 Chevrolet Impala.
The number one most common problem is related to the vehicle's electrical system
with 647 problems.
The second most common problem is related to the vehicle's exterior lighting
(91 problems).

### Table 1. Common problems of the 2004 Chevrolet Impala

##
PPMY Index and Problem Occurrence Trend

In our research we use the PPMY index to compare the reliability of vehicles. The PPMY index of a certain model is defined as the *problems reported per thousand vehicles per Year*. The total sales of the 2004 Chevrolet Impala in the United States are 279,789 units [1]. If the total number of problems reported by Chevrolet Impala owners in the last 14 years is 1203, and the age of the vehicle is 14, the PPMY index can then be calculated as

PPMY Index = 1203 / 279,789 / 14 * 1000 = 0.31.

For more information, refer to this page: A study of reliability comparison across Chevrolet Impala model year vehicles.

The following chart shows the number of problems reported during each of the service
years since the debut of the 2004 Chevrolet Impala in 2004.

#### Table 2. PPMY Index and Problem Occurrence Trend

Service Year | Number of Problems |

2004 |
2 |

2005 |
36 |

2006 |
65 |

2007 |
138 |

2008 |
181 |

2009 |
146 |

2010 |
118 |

2011 |
69 |

2012 |
62 |

2013 |
78 |

2014 |
127 |

2015 |
83 |

2016 |
31 |

2017 |
30 |

2018 |
0 |

##
Compare the 2004 Chevrolet Impala with Other Model Years

When making the decision between buying a new or used Chevrolet Impala,
the following table can be used to compare the 2004 Chevrolet Impala
with the Chevrolet Impala from other model years.
Note that the number of problems reported for the 2004 Impala is 1,203
while the average number of problems reported for the 23 model years of the Chevrolet Impala is 474.

### Table 3. Compare the 2004 Chevrolet Impala with other model years