So I took my car into the shop last week to have them run a smoke test and they ended up finding one bad leak and replacing the hose. Got it back from them and everything looked good, no more lean, fuel trims looked fine until about 30 minutes later. I got a P0171, was running lean and my trims were back in the 20% range. I took it back and watched them smoke it, then found 2 leaks, one little one in one of my hoses and then a pretty good amount of smoke coming from my leaky valve cover gasket. They told me that my best bet was to pay the $400 and get those replaced and that it would most likely solve my problem. To me this sounds unnecessary as the car ran fine for a while prior to taking it back into the shop but that being said I also didn’t see any smoke coming out from anywhere else. From what I have read on the fourm there is a lot of conflicting information. Any ideas on what to do?