My motor was tuned with shitloads of Tees for vac source as I didn't have a vac manifold at the time. The AEM fpr was T'd twice. A few weeks after tuning, I managed to install a vac mani and all sources (BOV, boost gauge, fpr, map etc..)now have their own direct vac connection on the vac mani. Shortly after, I noticed that when I was in boost I ran LEAN in the range of 12.5-13.5, did not dip below 12.5 at any psi (car was tuned for 12.1 with S200b). The only other change I did post tuning was I removed the VAFC that was in thar car when it was tuned but we ensured that all the settings on it was zero'd before we started tuning it, so I don't think this is the culprit. Could the stronger vac source that the fpr is now getting cause the AFR to go lean?