Hi all, I have had a U7194 predator for awhile now and have recently added a Airaid Jr. intake pipe with a drop in air filter and also put a 3" single in single out Magnaflow muffler/exhaust on my 2011 Silverado 5.3 Z71 4X4 with 6 speed auto. I have been running the canned 87 octane tune with DOD ...