Originally Posted By: dRock96Marquis
 Originally Posted By: Quickvic30
Really, never had a problem with that.

Yea, but wasn't your car dynotuned?

The tuner could adjust for your setup some right there and compensate to keep your a/f trim nice and flat. Some guy on here with no tune, or only getting a "mail order" tune can't adjust for that and as a result would run slightly lean from sucking in the unmetered air. It would be the same as if there was a large vacuum leak, as the MAF is not registering the extra incoming air. Know what I mean?
But why does the maf sensor need to know about air that is coming from the crank case, as the tube that goes into the air tube draws the air from the crankcase when the throttle plate is open and its all after the maf sensor to begin with. Im trying to figure out both of your guys reasoning. I also have a breather on my valve cover just like quick and have never had any problems and neither have people that i know that have the same set up with out a tune. Not saying that your wrong or not.
2012 Ford F150 Ecoboost

1998 mercury Grand Marquis, 58k miles slower than a turtle stock as stock gets