Ok I'm sure 99.9% of you y-pipe owners did this already but be sure to reset your ECU. I reset mine by disconnecting the battery for 30secs.......later to find out that doesn't reset the ECU. I left my battery off overnight (last night) which will reset your ecu for sure and it seems to have made a difference. My car just seems to be running stronger. I keep hearing conflicting opinions as to resetting the ECU. Everything from disconnect the battery for 10seconds to overnight. I really don't know the answer but overnight will do it fo' sho' What does resetting the ECU after a Y-pipe install do? And why does the battery need to be disconnected for over 1 min?

 

The ECU is adaptive to a certain extent and can adjust to increased air flow. Resetting allow it to re-learn the new settings with your mods. The ECU is using some kind of memory to store its settings that will not be erased instantly. The long term disconnection causes the memory to be erased eventually.

 

I'm a 4th genner but...I did this after installing my y-pipe, b-pipe, and 5th gen muffler. The car got a lot quieter after resetting and I've been getting excellent mileage gains. Power-wise, I'd say I felt the most right after installing it, but then I think I got use to the power. It's there, but it just feels like the norm now. I ran my car last night and it was definitely faster than before the mods and before the reset.

 

Ya my gas milage went to the ****z for the last two weeks (since I installed the Y). I hope resetting the ECU will help that. Also I find it pulls more on the highway since resetting.