The overall ratings of three Auto Parts stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Modine Manufacturing (NYSE:MOD) drops from a D (“sell”) to an F (“strong sell”) rating. Modine Manufacturing specializes in thermal management systems and components, bringing heating and cooling technology and solutions to diversified global markets. In Portfolio Grader’s specific subcategories of Earnings Momentum, Earnings Revisions, and Earnings Surprise, MOD also gets an F. Shares of MOD have fallen 3.5% over the past month, worse than the 1% increase the S&P 500 has seen over the same period. For more information, get Portfolio Grader’s complete analysis of MOD stock.

This is a rough week for Fuel Systems Solutions (NASDAQ:FSYS). The company’s rating falls to D (“sell”) from the previous week’s C (“hold”). Fuel Systems Solutions provides advanced alternative fuel systems technology and components for internal combustion engines. The stock gets F’s in Earnings Growth, Earnings Revisions, and Margin Growth. The stock has a trailing PE Ratio of 88.5. To get an in-depth look at FSYS, get Portfolio Grader’s complete analysis of FSYS stock.

Icahn Enterprises (NASDAQ:IEP) is having a rough week. The company’s rating falls from a C to a D rating. Icahn Enterprises is a diversified holding company involved in a variety of businesses. The stock gets F’s in Earnings Growth, Earnings Momentum, and Sales Growth. The stock price has dropped 2.3% since last month. For more information, get Portfolio Grader’s complete analysis of IEP stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.