A local mechanic has told me there is 16 codes that are showing when he scanned

According to him they are current. I had taken it to him because of a miss fire code and he had done a leak down test because cylinder #4 was showing low compression. @85. He said that it needed intake valves along with possibly clutches in the trans along with a bunch of other stuff. It is so frustrating with some of these mechanics.

Yep. Get a second opinion