Anyone Really Know?
 

Does anyone know the real deal about performance mods, and if the ECU
needs to be reset? I've seen so many posts about mods being canceled out by the the ECU due to the program. I know the ECU can be flashed, like the people over @ Technos Sq. But do you need to reset, disconnect the battery
if so for how long? or is this a wifes tale also, I'm not a newbe in this world, but don't want to drop a chunk change, without some return......
Hapstr !

It's always a good idea to reset the ECU after installing a MOD. Generally, when you're working on anything electronic in your car, you're 'supposed' to disconnect the battery. I'm guilty of not always doing it. Some have noticed their car runs poorly after installing a MOD when they don't reset the ECU, but notice an improvement after doing so. What you want to do is leave the battery disconnected for 10 minutes, or so. After you reconnect it, take the car out and really hammer the throttle. Take it to redline, or close, in the 1st 3 gears. This will help the ECU recalibrate the air/fuel mixture, which helps it run better.

The new obd II electronics will not reset by diconnecting the battery,all this does is set a code that the battery was disconnected. The ecu has to be reset with a compatiable scan tool. Flashing the ECU is the way to reset the programing of the prom in the ECU , older cars pre 95 have replacable proms or {chips} this is how you get updated to run more fuel,timing ect. Only word of advice is do your home work be fore your mods.

Hey; rosscoe the info is very much appreciated, my 03 /Z33 coup is a fun
ride. But, just don't want to waste the time and money in adding things like
K&N Typhoone intake and Borla exhaust, and get nothing in return. Or
something that sounds, like it should go fast. Your advice about doing my homework is what I'm trying to do, however getting real info about this subject is like mining hens teeth, I don,t know what or whom to believe.
As I read your info, It tells me that I do need to get the ECU flashed to take advantage of latent mod I may add. This is fine, but who can flash the ECU for me. And if I have this done there is the question of warranty, this is why I chose not to have Technos Sq. do a flash at this time, it will void the warranty. This is info I got from Nissan National, their comment was
" Any change to the ECU factory program will result in automatic suspension
of the powertrain warranty, the rest of the warranty remains in effect".
This seems to be a larger problem than it's worth. Still looking for answers?
But thank you for your response. Hapstr!

Not to point you to another site but there is alot of info on 350s on my350z.com some of the dealers have upgraded ecus with higher rev limiters and timing and fuel adjustment. sorry to say there are more 350 owners over there too.

From what I hear from other owners, many NA mods won't produce the gains that they would if you had an ECU flash.
Some people say they've gained XX hp/tq with an intake, exhaust, plenum, y pipe, cams, test pipes...the list goes on and on. Then there is the group who say they haven't gained jack from $2000 worth of mods (including some car mags) due to the static timing maps in the ECU.

After months of researching, mostly at my350z.com, it seems that yes, NA mods will produce some gains. People have the dyno sheets to back this up. But the full potential of these mods aren't reached because of the stock ECU limitations/restrictions. Point-in-fact, check out the people who have had the ECU reflash. They have fairly decent gains as compared to the gains before the reflash. From checking out Technosquares site, if any mods are added the ECU needs to be reflashed again to get the maximum gains. It looks like this would be an ongoing (expensive) process if someone continued to upgrade their car.

If you don't want to get a reflash, check out the Greddy eManage. It's not a substitut for a reflash but it does allow you to adjust a/f curves/ratios, etc for a fairly low price.

Just my $0.02.

Good luck!

Leave it alone. If you decide to upgrade ECU go NISMO ECU & just disconnect & reconnect battery. Drive normal at highway speeds. NISTUNE will be your most reliable ECU tune. MINES in JPN does re-flashes & I personally wouldn't get mine done here, be cautious.

-Aviation NASA Electrician Retired