Please read and post the YEAR AND MODEL OF YOUR CAR.
To make thing more easier for another member to help you with question or problem about your car.
Please give us a brief history of the car.
Year, model, mileages, aftermarket equipments, maintenance history, body repair from the privious accident, first owner or second owner and so on.
If you have question about CEL ( Check Engine Light) please give us the code to work with, such as P0440, P0750 and so on. DO NOT POST AS " I GOT CEL, PLEASE HELP".
For some of the squeaking and rattle issue please be more specific about the road condition, temperature( cold start , cold weather or hot weather) , and speed of the vehicle. Please keep in mind that we are not hearing the noise you're hearing because we are on internet and the problem may never get solve.
Please keep an open mind when reading another people post that his suggestion may not fix your car. He may had the same condition with his car in the past and tighten the gas cap fixed his car, but tighten the gas cap solution may not fix your car.
One more thing, SEARCH before you post.