to do it properly, dissconnect battery overnight... in the morn, connect your battery, and warm up car till the fan kicks on without touching the gas pedal. that is supposedly the "Proper" way of doing it as far as i know.

 

Once the fan kicks on, I think you're supposed to cycle the ignition again.

 

"cycle the ignition again" what does that mean? Like shut it off and then turn it back on?

 

Yes.

 

From Scoobymods.com:

ECM (Engine Control Module) reset instructions
Special thanks to RiftsWRX for allowing us to post this mod...

1. Disconnect the negative battery lead.

2. Let the vehicle stand for at least an hour. LONGER if need be. The motor must be cool to the touch.

3. Once cool, reconnect the battery lead, close the hood, and start the vehicle. DO NOT touch the gas at all!

4. When the car has reached operating temperature, or the cooling fan has gone on and off once, shut off the car.

5. Turn the vehicle back on and go for a drive based on what you want the car to do. Want every bit of horse power? Take 1st and 2nd gear to red-line a few times. Want to teach the computer that your just a commuter? Drive nice in some various traffic conditions for about 20 minutes. Then go home and shut the car off.

6. After that? Drive the car like normal, you've paved the way for what you'd like the computer to aggressively try and learn. It will take a few tanks of gas before the computer will be "tweaked" for one manner of driving or another. The first tank may also show a drop in MPG around town, that will go away soon enough.

 

Man every time I hear this stuff, all I can think of is "VOO DOO".

If the ej20 ecu is always learning and always adjusting its curves, why would all this matter? Wouldn't then the case be that if you drive like a granny for a week you're stuck with that until you spend a week driving like Mario Andretti? I've seen Shiv's (2nd hand?) post about this holding the RPMs just right and all for the quick tune after a reset, etc... is there any proof of this stuff? Or is it just voodoo?

As far as I know, the only left-foot tuning that really works by dyno proof is when Sport Compact Car did many, long runs at over 100mph through Montana. They said their subsequent dyno runs showed 10whp more in the upper ranges. From my own experience, my car seems a lot happier after I do this... happier ... I mean I feel alot happier after I do that

 

Honestly, I couldn't tell you if this works or not, but I look at it as just part of the mod. Anytime I install something like exhaust or an intake, I just disconnect the neg. bat. lead as the first step. By the time I'm done with the mod, put my tools away, etc. it's already been about an hour.

Then, I'm gonna drive the car around like a freak once I've installed the mod anyway, so I might as well just connect the lead again, start the car and let it run for a cycle, shut it off, start it again and go drive aggressively somewhere testing out the new mod. With a few easy extra steps, I have reset the ECU. Even if it doesn't do a damn thing, I still like knowing that if it does do something, I might be getting that little extra power.

 

Last night I helped my cousin install his HKS Carbon-Ti. It looks sweeeeeeeeeeeeeeeeeet. But we didn't disconnect the battery when we started working or didn't reset the ECU in any manner. Will it hinder the performance? hp?