so the ecu should be restet for 12hrs???
im getting real ****ty gas mileage, i mean like 16mpg, and do i have to reset the battery and then just connect it the next day, or is there anything else that needs to be done???

 

Precisely. The change in timing (or tables) is the reason for the change in power. With A/F being a lesser motive.

There are 3 maps the ECU works from. (1) Agressive, (2) Normal and (3) Safe mode. A ECU reset will put you on the first map.

The ECU will keep you on the first map untill it is given a reason not to. IE the ECU constantly monitors for ping both in frequency and intensity. If ping exceeds a threshold for frequency and/or intensity it will down select to the 2nd map with an associated reduction in timing. The reduction in timing is safer for the engine. Ping can be caused by running lean, bad gas or other reasons.

Interestingly enough, the first map gets the best gas milage because of the timing advance.

Short term depends on how you drive, the gas you use and your cars state of tune. If your car is running optimally, you put in good gas and drive vigorously, you probably won't see a change with a ECU reset.

But either way, a ECU reset can make an objectively measurable difference.

 

16 MPG IS real chitty.
You can get less than that on the race track but if you are doing that on the street, it almost sounds like something is wrong with the A/F or you are driving like a mad man.

 

For those that are setting their ECUs, how often are you doing it?

 

I just tried it today and the ONLY difference I found was that the tranny shifted a bit faster and I'm not fully convinced that its not all in my head I can usually do the ECU reset in a minute or two so its no big deal but I find that the laggy tranny doesn't bother me too much. BTW, my tranny shifts at exactly 6400 rpm after installing the grounding kit so I think the kit works better than the ecu reset for tranny responsiveness.

 

After the first lap with 100 octane in the tank or before dynoing. Thats about it. I'm too lazy to reset my clock every time. But when I do, I just disconnect the battery ground and push the break pedal for a quick reset.

 

whats a/f??

and no actually im babying it still, i get on it once in a while but not like a mad man???
what do you recommend i do??

 

Bring it to the dealer and ask them to check it and diagnose any potential problems. 16 is too low. My truck gets better than that.

A/F is the air/fuel ratio. You may be running excessivly rich. In addition to giving you low gas milage, it would stink and make sooty exhaust. You have any of that?

 

16mpg actually sounds pretty normal for a 5AT in Chicago style traffic in the summer with the A/C on and/or with a driver that gets on it here and there on occassion. On the highway, the 5AT car will do significantly better, but around town things can be pretty dismal with these cars. I typically see 18-19mpg with 80% city and 20% highway and I really don't have much traffic to contend with. The EPA rates the 5AT at ~18mpg city and that's with them *****-footing it around.

 

i dont beat on my car at all whatsoever, and i can understand that kind of mileage with the a/c on but it seems like its the same with a/c or without, the hwy is a little better though with 80% hwy and 20 city i got like 19mpg, but in city with or without a/c it hasent been better than 16mpg yet

 

What year and drivetrain is your G? The X's will suffer worse MPGs because of the addition drag of three additional axles, an extra differential, fluid drag, and hauling around about 130lbs more weight.

 

i got a 03G its got 36k miles on it
and im pretty pissed off about that gas mileage, but besides for that i love the car

 

How to do you reset ECU. Is this something i can do from inside the car...

 

I have to say that this thread has been the most technically interesting and polarized discussion I've read in the short time I've been here. No pissing contests, no name-calling, no juvenile I'm-taking-my-VQ-and-going-home attitude from anyone.

Two observations: One, this discussion could never take place on the coupe forum; and two, if the three air/fuel/spark advance maps really exist in the ECU, I've learned something really interesting. Thanks.

But I still stand by my assertion that resetting the ECU results in, at best, very short-term performance gains. Might be good at the dragstrip though if they'll let you stage and take a break for several hours before making your run. The guy in the Camaro next to you might get impatient, though.

 

Well I did it. I reset my ECU almost 2 days ago and here's what I've noticed over the past 36 hours of driving:

1) The intake (Z-tube and powerduct cover removed) got much quieter. The induction noise doesn't have near the authority it had prior to the reset. This is the same exact thing I noticed in my Maxima after a reset. It will probably be a few more days until that sound comes back

2) The tranny shifts slightly firmer during normal driving. I kind of expected this because the tranny is adaptive and it's learning my driving. It still shifts at 6400rpm it left alone and 6800rpms if manually shifted, just like it did prior to the reset. WOT up/downshift firmness is the same.

That's it. I noticed absolutely no increase in power. If anything, the car feels slightly less responsive, just as I noticed in my Maxima after resetting the ECU.