When disconnecting the battery to reset the ECu, how many hours must the car sit?

 

mike best bet is going to Autozone and asking one of the guys to reset it or you could try doing it manually via the ECU. i don't recommend ecu method since we have 99's with a small screw.
I am pretty sure disconnecting battery doesn't clear codes since i tried this a while back when i had my O2 sensor code.

 

Hmm, well I am not really clearing codes per se. I dont have a CEL and Autozone wont come out to your car unless you have a CEL. My car is sitting disconnected and dead to the world as I type. BTW, thanks for your help earlier today.

 

Disconnecting the battery does NOT reset the ECU. I tried to reset it this way, but it does not clear codes.

To correctly reset the ECU, look under your dash (behind the center console) and find the ECU unit. There's a little screw you can turn with a flathead that is facing the driver's side. Turn your ignition to the ON position (don't start the car). Turn the screw all the way clockwise (to the right) until it doesn't turn anymore. Hold and wait 2 seconds. Turn the screw back all the way counterclockwise and hold for 2 seconds. Repeat the process again and you will hear a bit of electronic noise come from the ECU (telling you it's resetting itself).

 

The 99SEL's ECU screw is small and recessed. It's a Pain in the ****. But I guess thats the only way.