Hi! I have had my 09 V6 since it was new. After the warranty expired, I installed a Ford Performance Cold Air Intake and Bama tune. They too have run fine for many years. The car has ran fine until a month ago when it fuel gauge dropped to E instantly. The dealer said the jet fuel pump was bad and to tank from getting low while I wait for parts. Thinking of saving gas, I attempted to to switch to my fuel efficiency tune from Bama. The car wouldn’t start and I could smell gas. I swapped back over to the old tune and the car still had rough start but eventually started. The engine idle was very rough. Thinking that the tune just needed to settle in, I drove it for 200 miles. The issue persisted so I tried again reflashing the tune. The car now starts fine, but it still idles rough. The RPM goes as low as 450 and almost stalls. The whole car shudders when it’s this low. It will bounce up to 2000 without any pressure on the accelerator. The car drives normally after a few minutes, but this problem re-occurs on start-up with it being much worse on cold-start-up. The check engine light only gives errors for “system too lean” on both banks. Any suggestions? Thank you in advance.