# is it possible to keep a steady a/f ratio? **URL:** \ **Category:** General Reprogramming / Tuning\ **Created:** [November 23, 2009, 10:52pm UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045 "2009-11-23T22:52:58Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![acuralover](https://forum.g2ic.com/letter_avatar_proxy/v4/letter/a/bcef8e/32.png) [@acuralover](https://forum.g2ic.com/u/acuralover)\ **Post date:** [November 23, 2009, 10:52pm UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/1 "2009-11-23T22:52:58Z")
i just installed my aem wideband normally without hooking it up to the s300 but at idle it jumps usually from 13.8 to 15.2 ive tried almost everything… so the question is can i keep it around 14.6 to 14.8 or is it impossible? ---
**Author:** ![BLKACK1](https://forum.g2ic.com/user_avatar/forum.g2ic.com/blkack1/32/123_2.png) [@BLKACK1](https://forum.g2ic.com/u/BLKACK1)\ **Post date:** [November 25, 2009, 11:26pm UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/2 "2009-11-25T23:26:11Z")
In closed loop, NO In open loop, Yes ---
**Author:** ![BLKACK1](https://forum.g2ic.com/user_avatar/forum.g2ic.com/blkack1/32/123_2.png) [@BLKACK1](https://forum.g2ic.com/u/BLKACK1)\ **Post date:** [November 29, 2009, 5:49pm UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/3 "2009-11-29T17:49:49Z")
I replied to your email man, you ever get it? ---
**Author:** ![xenocron](https://forum.g2ic.com/user_avatar/forum.g2ic.com/xenocron/32/95_2.png) [@xenocron](https://forum.g2ic.com/u/xenocron)\ **Post date:** [December 7, 2009, 4:04am UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/4 "2009-12-07T04:04:58Z")
[QUOTE=BLKACK1;2094542]In closed loop, NO In open loop, Yes[/QUOTE] Sorry, I have to say this information is wrong. Depending on the engine configuration, you should be able to idle the car steadily at 14.7 AFRs or even leaner if so desired. ---
**Author:** ![BLKACK1](https://forum.g2ic.com/user_avatar/forum.g2ic.com/blkack1/32/123_2.png) [@BLKACK1](https://forum.g2ic.com/u/BLKACK1)\ **Post date:** [December 8, 2009, 3:08am UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/5 "2009-12-08T03:08:52Z")
please explain:corn: I not doubting your statement, it just i was under the impression that in closed loop, the ecu is (and pardon my terminalogy here) constantly switching back and forth. How would it stay steady at a certain air to fuel ratio? ---
**Author:** ![xxfile](https://forum.g2ic.com/letter_avatar_proxy/v4/letter/x/c57346/32.png) [@xxfile](https://forum.g2ic.com/u/xxfile)\ **Post date:** [December 14, 2009, 7:54pm UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/6 "2009-12-14T19:54:44Z")
I thought the ECU switch back and forth trying to keep a constanct A&F raitio? ---
**Author:** ![ninezeroteg](https://forum.g2ic.com/letter_avatar_proxy/v4/letter/n/91b2a8/32.png) [@ninezeroteg](https://forum.g2ic.com/u/ninezeroteg)\ **Post date:** [December 14, 2009, 10:32pm UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/7 "2009-12-14T22:32:50Z")
Xenocron is right… In closed loop (at idle) the ECU will receive a signal voltage from the o2 sensor letting the ecu know whether the AFR is rich or lean. The ecu will react accordingly to that signal in order to get the AFR dialed in to the o2 sensors target AFR, 14.7. In open loop, the ecu will just use the fuel maps as they are programmed, along with any ect and iat corrections that are being called for. If programmed correctly, you should be able to get it to idle at 14.7. Does either open or closed loop mode ever just sit right on 14.7 and not move around between 14.60 and 14.80? Maybe for a second, mines is constantly moving but within that range. If you had your injector offset setup correctly, with top of the line injectors and a good electrical system, you could probably get it to hover closer to 14.7 on the nose constant. ---
**Author:** ![acuralover](https://forum.g2ic.com/letter_avatar_proxy/v4/letter/a/bcef8e/32.png) [@acuralover](https://forum.g2ic.com/u/acuralover)\ **Post date:** [December 26, 2009, 7:43am UTC](https://forum.g2ic.com/t/is-it-possible-to-keep-a-steady-a-f-ratio/89045/8 "2009-12-26T07:43:18Z")
hey man yea i got your email its been cold out here that i havent even bothered touching it … but its starting to annoy me seen that guage go from 13.8 to 15.5 … is there a problem with my aem wideband hookup ? could it be a leak before the bung or at the 02…and i dont have the aem wired to the hondata