Your factory C3 (1982) and C4 (1984-1993) is equipped with a diagnostic port. This port allows technicians to diagnose and trouble shoot engine and computer trouble codes. The port comes with a cover which is designed to keep out dirt, grime, moisture, and dust which can prevent accurate readings. Often, the tabs on the factory cover break off so it simply won't stay in place. Many owners then decide to just leave it off rather than replace it like they should.
Vehicle Fitment:
The Vehicle Fitment Guide is to be used as a general reference. The data has been provided by our suppliers and manufacturers and may contain errors or incorrect data. Always refer to a professional to verify correct fitment for your vehicle.
