Poor gas mileage connected to idle learn procedure

[auditude]

Originally Posted by RidgeDOC

The reason is sometimes however to meet emission regulations. By opening intake or exhaust restictions placed by factories to meet emissions you can at times gain significant HP. At least this is true for motorcycles for which I have more experience replacing stock with aftermarket pipes. Should be true for cars trucks too eh?

In addition to emissions, also tractability and noise affect the power that the OEM's put out. You can gain ultimate HP at the expense of your bottom end I(lower rpm torque I'm saying), for example, but the factory has to put something out that is more usable for the majority of their customers so it ends up being a compromise among a bunch of factors.

Economies of manufacture play into it as well. If we want to spend the money doing stuff, generically speaking such as porting the head or ceramic coating the exhaust, etc, then we might be able to extract more power than the factory was willing to spend on, particularly if we have different goals or would tolerate a different compromise among all the factors.

[nwsnowman]

I completed the idle learn reset on my 06 this weekend and can already tell a difference. It idles and shifts at lower points and finally when I take my foot of the gas the truck actually coasts and drops RPM's to 1000-1500 rather than staying at 2000-2500 with my foot off the gas. By the way I know disconnecting the battery reset my trip odometers but does anyone know if it resets the oil life as well? I changed oil and reset it about 700-800 miles ago and it still says 100%, not sure if it reset or has not dropped yet.

[boobai]

Your oil life is not reset. Neither is your odometer. Your trip meter is probably reset though.

[nwsnowman]

Thanks boobai. Now only if I could figure out how to turn back the odometer and keep my warranty going, hmmmm........

[ace5000]

My idle is running at about 800 it appears.

Has it been determined if it is possible to reset the ECU without the dealer?

Thanks.

[ace5000]

Anyone? Can we do the reset at home?

[happyjoey]

I just compleated my research on idle learn, mostly here on ROC and in my shop manual. My thinking is that the on board computer (PCM) has to be reset. It can be done via Hondas hds (honda diagnosic system) a plug in system avaliable at the dealer, or maybe by disconecting the battery for at least 5 minutes, as explained by a fellow ROC er. It looks to be a process that needs to be done only if the idle is out of range (750 rpm) or the PCM has been replaced. Just doing the engine rpm stuff is not going to get er done. I do not think I need to do a idle learn process now that I have done my homework. Again this ROC has saved my time and effort THANKS

[Webwader]

The tach at low RPM is not very accurate, or the angle makes it deceptive. I thought mine was idling at 850-900. I had the dealer check it and I don't remember the figure, but it was lower than that and within specs. After I got my Scanguage I found that it was idling in the low 700s.

[DavidinGA]

So have we come to any real conclusion?

[arteegee]

Originally Posted by DavidinGA

So have we come to any real conclusion?

Long ago if memory serves.