Lose power while driving tighten up gas cap its fine for awhile

Tightening your gas cap has absolutely nothing to do with things working better. An engine performance diagnostic test is required. Have your engine tested for the presence of ignition spark, fuel delivery and proper air. Ensure there are no restrictions to the exhaust system. One (or more) of those elements are missing from the equation causing the power loss concern when it happens. When you find out what it is, it will be necessary to drill down further to see what is causing the loss of it. Guesses would be fuel pressure concerns, air flow concerns. But you have to test. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops