o2 sensors
Thread Starter
Teching In
Joined: Nov 2001
Posts: 33
Likes: 0
From: australia
o2 sensors has this idea been looked into ?
something to trick the o2 sensors into reading slightly richer, so the pcm will lean off a bit. after all this is where any relearning comes from, if any.
all the tricking comes from other areas, is their a reason no one goes via the o2s.
something to trick the o2 sensors into reading slightly richer, so the pcm will lean off a bit. after all this is where any relearning comes from, if any.
all the tricking comes from other areas, is their a reason no one goes via the o2s.
Thread Starter
Teching In
Joined: Nov 2001
Posts: 33
Likes: 0
From: australia
Re: o2 sensors closed loop ah, isn't that too rich as well though? the benefits of a maf maft etc in closed loop are learnt out during closed loop, but still remain at Wot when out of closed loop. hence the idea, was wondering if its been tried before already, and i'm sure it has by someone. If so what were the results..?
For the street this will have the benefit of lower fuel consumption as well while in closed loop. of course can get a new base pcm program/edit to correct this, but maybe the 02s are a cheaper way to go. If they have no major drawbacks.
[ December 12, 2001: Message edited by: vt2vx ]</p>
For the street this will have the benefit of lower fuel consumption as well while in closed loop. of course can get a new base pcm program/edit to correct this, but maybe the 02s are a cheaper way to go. If they have no major drawbacks.
[ December 12, 2001: Message edited by: vt2vx ]</p>
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: o2 sensors During closed loop (non-wot normal operation) your mixture is kept at a 14.7:1 ratio (called a stoic ratio) by the ECM based on readings from the O2 sensors (14.7:1 = .450mv on the O2 sensors.) This "stoic" fuel/air ratio is the theoretical optimum for fuel consumption and clean emmisions.
I see no reason to lean the closed loop fuel/mixture and as I said before, there are easy, tried and trued ways to manipulate the WOT mixture. <img src="gr_stretch.gif" border="0">
[ December 12, 2001: Message edited by: Colonel ]</p>
I see no reason to lean the closed loop fuel/mixture and as I said before, there are easy, tried and trued ways to manipulate the WOT mixture. <img src="gr_stretch.gif" border="0">
[ December 12, 2001: Message edited by: Colonel ]</p>
Thread Starter
Teching In
Joined: Nov 2001
Posts: 33
Likes: 0
From: australia
Re: o2 sensors thank you, thats a good reason if the af is 14.7.
during the year or so i've been into these motors i have never seen or heard what the af ratio is supposed to be in closed loop operation, only at wot.
I hope our pcms over here are the same as the US one in that area. I have found and many others over here that fitting a maf, exhuast etc will give you better wot power, which tends to remain over time. however the 'butt feel' response, extra power feeling (whatever you want to call it) at less than wot, tends to go away after a short period. this will be the pcm learning back to its base setting in closed loop, a pcm reset then brings back this lost (learnt out) power in closed loop for another short period. while wot power remains all the time.
So you can only suppose from that the bolt ons also do something to improve closed loop operation also, until it is learnt out. If closed loop is 14.7af then it must be due to increased timing or something else.
Sorry just trying to understand how to keep the closed loop benefits <img src="gr_eek2.gif" border="0"> , i understand the Wot ones <img src="gr_stretch.gif" border="0"> .
during the year or so i've been into these motors i have never seen or heard what the af ratio is supposed to be in closed loop operation, only at wot.
I hope our pcms over here are the same as the US one in that area. I have found and many others over here that fitting a maf, exhuast etc will give you better wot power, which tends to remain over time. however the 'butt feel' response, extra power feeling (whatever you want to call it) at less than wot, tends to go away after a short period. this will be the pcm learning back to its base setting in closed loop, a pcm reset then brings back this lost (learnt out) power in closed loop for another short period. while wot power remains all the time.
So you can only suppose from that the bolt ons also do something to improve closed loop operation also, until it is learnt out. If closed loop is 14.7af then it must be due to increased timing or something else.
Sorry just trying to understand how to keep the closed loop benefits <img src="gr_eek2.gif" border="0"> , i understand the Wot ones <img src="gr_stretch.gif" border="0"> .
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: o2 sensors If the purpose is to lean the mixture you can do that through porting of the MAF sensor, a MAFT, or HPP3 "Power Tuning."
The O2 sensors need to read properly for closed loop operation. I don't think you could trick them at WOT only.
The O2 sensors need to read properly for closed loop operation. I don't think you could trick them at WOT only.
