Q: 09 Nissan Altima makes a loud rattling sound while driving at a light, barely starting it and so on it’s not continuous.

Hi Stephanie. Thanks for contacting us tonight. I’m not sure what a flex tube is in regards to your Nissan Altima, but it is possible that the mechanic meant to the flex pipe. This is a component that secures the exhaust system to the vehicle and can cause a rattling noise over time. However, there are a few different locations of flex pipe, so without knowing which one is damaged, it’s hard to give you an estimate for replacement. It might be best to have one of our mobile mechanics complete an exhaust inspection, so they can verify the component that is damaged so the right repairs can be made.