Hey guys,

So I just installed stock injectors on my car to start diagnosing my hard starts and rough idle, when I put them in with all the rest of my settings returned to stock I got a +20% fuel trim at idle, so the car is running way lean. I have no boost leaks or vacuum leaks.

Tonight I was playing around with my MAF and I decided to pinch off the PCV line that runs from the valve cover to the intake pipe, my trims immediately dropped 15%.

Now the line itself isn`t leaking and its connected after the MAF so logic tells me that the air is metered but how can it be effecting the fuel trims then? Please chime in and let me know if this is normal behaviour or not.