[jblackburn]

This is very likely a vacuum leak.

Check out the PCV system for sure - the hissing valve cover is the most common, but also check for the orange dot (check valve) in the intake manifold. Make sure that the tube on top of that port on the intake manifold is still making a firm seal (there's an O-ring inside that should keep a snug fit on it and requires a little bit of pressure to get back on).

If all of that checks out, an air/boost leak around the throttle body pipe is also a common one.

 

[jblackburn]

Hey thanks for the input! I greatly appreciate it. I did have a boost leak at the throttle body I have since replaced the throttle body gasket and fixed that not having this issue. The car threw a P0171 today confirming the valve cover needs to be replaced. I couldn't hear a hissing from the diaphragm but I could near the back of the valve cover around the fuel rail. Would this just be leaking from where the valve cover meets the cylinder head?

Probably a leaky gasket, or maybe bad internally without blowing the disc yet, but they're so prone to failure I'd just change the whole thing.

Be sure to put some silicone in these locations when you reinstall the new one near the cam gears.