View Full Version : air to fuel ratio reset, check it out

12-31-2008, 06:02 AM
ok so i found this on 6gcelicas.com

Resetting your Air/Fuel Mixture Ratio
Original Author: mkbak Approximate Time: 10-15 minutes Required Tools: Needlenose pliers If you've noticed lately that your car has been running awkward or idling at very low rpms or even idling roughly, then your ECU may need to be reset. It is also a good idea to reset your ECU if you've added any performance mods like a header, intake, exhaust, etc. Doing this will let you take full advantage of your mods and reset your air/fuel mixture ratio so that you can get better performance.

Here's how to reset your ECU. First, start your car and let it warm up. When it's reached it normal operating temperature, turn the car off. Then, pop the hood and remove the relay fuse box cover and remove the following fuses: the Hazard fuse, the EFI fuse, and the ECU fuse. Take them out and leave them sit out for 1 minute. Then when the minute is up, put the fuses back in and start up your car. At this time the ECU is being reset so you can take advantage of your mods and get better gas mileage. When you start it up, let it run for exactly 10 minutes, then turn your car off. then start it again and you may notice your car idles better. From that point on you may have better gas mileage and your mods will be put to use.

Please note that this may not solve any problems, but it cannot hurt.

it works oh it works, doing this made my car come alive. no joke, every modded celica owner should do this.

i idled my car until operating temp, then shut it off and pulled the efi fuse, efi main realy and the hazard fuse for 1 min, then reinstalled and ran my car at idle for 10 min, then shut it down and started it up and took it for a drive and holy cow does it drive.

one of the guys over at toyotacelicas.com had the same results that i had. try it and tell me what you think, but you must try it. :burn:

12-31-2008, 07:24 AM
The reset procedure on any 5th gen Celica is simply to pull the EFI fuse for a minute.

This can sometimes not be sufficient though if there are still codes stored. To remedy this, pull off your Negative battery cable and wait 10 minutes. Pull EFI fuse at this time as well. Next, after the 10 minutes are up, re-install the Negative cable and then the EFI fuse.

Just FYI, this is a FULL ecu reset, not only for the A/F.

12-31-2008, 10:45 PM
Is there any truth to this? Not the ECU reset, but the need to reset the ECU every so often or after a mod.

Just sound phony to me. If the electronics NEED to be reset every so often OR after a mod, I'd be a bit concerned. This would mean that the car is always running off of the same map regardless of loads, VE, ambient air temperature, etc. I'm pretty sure the electronics were engineered to compensate for such changes, ie. air temp, VE, etc. When your setup exceeds the capabilities of the electronics is when you need to upgrade to better electronics. A simple reset should not gain you any optimization of a set up except if there are stored codes which may limit performance, ie previous fuel cut will put you in limp mode until resetted.

12-31-2008, 11:24 PM
the need to reset the ECU every so often...

No, definitely not.

It just resets the ECU to factory defaults as you have removed the power. This is not a trick, this does not reset A/F's either. It simply, turns off the power.

If anything also, your car will run more conservative at first as well until it has determined your regular knock count and timing.

12-31-2008, 11:25 PM
No, definitely not.

agreed, this guy is making such a big deal about this on the other forum lol.

01-01-2009, 05:39 AM
well it works, don't knock it till you try it

01-01-2009, 06:59 PM
It's just relearning, which it does all the time anyway. It also still doesn't affect WOT performance at all, which is open loop :squint:

01-02-2009, 01:57 AM
Hey guys,
he was not the OP. He was asking for clarification on the subject, and I'm pretty sure he knows the score now. So, let's ease up and leave the name calling at the door.