the issue is the location of your pcv port. It HAS to be AFTER the maf. The engine in the crank case is technically metered air. So by having the pcv port before the MAF you are changing the airflow that is being metered. Also: having less than 6" of run between the MAF and throttle plate can cause serious air flow frequency issues which can lead to the maf getting strange readouts during certain conditions such as off throttle and snap throttle.