Now my left direction signal won't work, and my flood lights/high beams won't turn on. Didn't really notice any change in performance with the car either.

I don't understand why everyone says to reset your ECU, it won't do anything....I was told this a few years ago and it did nothing. I have since been told the ECU automatically learns new settings and mods just after a few minutes. Thats weird that your turn signals don't work and lights.......check your fuses, i bet some of them might have blown when you messed with the battery.

the change is more noticeable with automatics...

yeah, u blew a fuse! or two...

Yey, taking it to the dealer tommorow, let them deal with it.

THe reseting the ecu thing just doesn't make sense to me. So basically the theory is the ecu is set to "learn" your driving style, ok that makes sense. But to think you loose performance if you drive "normal" is rediculous. So basically you need to redline it out of every stoplight so that shifting stys fast and HP stays at 298. If that is true the programers would should be fired. I was in my firends audi rs6 the other day and when they say it learns your driving it means it learns how you are driving at that moment. I was really gettiing on it and then I calmed down and the AT was holding it's gear at 5k rpms as I was crusing down the fwy, and as you are breaking it downshifts right were you would keeping the rpms up. It was by far the nicest AT's I've driven. My friend said don't bother manually shifting it, the car will do a better job than you will and he was right!
Anyway, back to my original point, the thought of a "learning ECU" is that it should do what this rs6 did depending how you are driving now.

I guess the lesson here is....don't try the "12hr battery thing"

Hopefully it's a quick fix.

Not to hijack......but an auto will shift better than you can with the manual mode in an auto, but when i had an auto I would use it when i wanted to hold a gear out while not on the gas, then if someone was about to race me I could just punch it without it having to downshift....that was about the only benefit of MM.

I was once like you guys, I didn't believe in the ecu reset either. However, as of last Sat. the ecu reset WORKS.
However, it wasnt the disconnecting the battery method. Mel, who I met from 2.19 dyno day, he reset my ecu by stepping on the gas pedal a few times with other precisely timed actions. At first, I really didn't believe he did anything. There were two more cars before me, I still had some time before it was my turn to dyno my car.
I was leaving the plaza, as soon as I got on the street... WOW!
My car was a different animal. I forgot to tell you guys that I had reverted to my stock air box the night before.
I can't say anymore about the ecu reset other than the fact that it works.

I believe technosquare has the "pedal" method way of resetting the ecu.

I take mine to Infiniti whenever I want my ECU reset. I leave it to the pros...they plug in their handheld computer thingy & BAM it's done in 10 sec.

The battery thing may not be the best way and don't take off your + terminal if you do. The pedal reset was proven at the track and even on the dyno I believe.

The system will detect new airflow if it is there instantaneosly I would presume. But a fresh ecu is the strongest ecu and over time there are algorythms that dictate a slower shifting tranny and a different AF map based on LONG TERM habits recorded over a several day period by the ecu. It can't get any slower doing a reset and if you hammer it all the time you may never need to reset making them seem impotent, but they do work and rather well.

Don't do the 12 hr battery thing. There is a pedal sequence you can do to reset the ECU. Try that and see if the lights work again. The instructions are in a sticky thread in the mods or DIY section.

I do the pedal thing all the time, I just decided the other night, since I was working on my battery to give it a go. Big mistake. On my way to Infiniti right now.