So I'm planning on getting my G tuned but not at the moment because I have a lot going on financially. I managed to score a brand new Gen 3 Stillen for $460 shipped so I jumped on it. However, at the moment I have Berk HFC's and then a half assed exhaust... I replaced the factory resonators with vibrants and then have an axle back Tanabe. So a majority of the piping is that tiny factory 1.5" pipe. Can I get away with running without a tune for a few months?

 

You can get away without a tune even with a bigger exhaust and the Stillen CAI. The ECU maps have enough leeway to accommodate the changes. That said, the maps aren't flexible to fully utilize the higher airflow. You would have discovered this with some time reading this forum.