altima idle noise

2006 Nissan Altima S 2.5 All stock, no modifications It's harder to tell from the video but when the car is started up it sounds like it doesn't have a muffler and is super loud. Also, when idling it shakes and makes this prominent rumbling noise that for some reason didn't do it in the video...

This 2001 Nissan Altima SE has a 2.4 liter KA24DE 4 cylinder engine with an automatic transmission and it has a few problems. First of all, Check Engine Light Reads "Random Multiple Misfires" When we bought it, it has a slight idle problem. I thought it needed a tune up with new sparkplugs...