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Discussion Starter #1
So since updating my sct to show OAR, I have found what I believe is the reason my trucks power feels very inconsistent.

The OAR will stay at -.96 to -.88 if I am driving nice and easy with it keeping the rpms down and easy on the throttle.

However, if I am hard on the truck or ever giving it WOT the OAR takes very little time to go into the positives and on few occasions has gone as far as +.96. This same issue seems to be even worse if I drive it in manual mode the OAR is almost guaranteed to stay in the positives.

Anyway, I cannot figure out for the life of me what would be causing the OAR to react like this, people are saying knock but I am running water methanol so I find that very unlikely of being the cause. Unless my knock sensors are just bad and need replacing.

I have also been told maybe the exhaust is triggering it but I looked underneath and the exhaust is not contacting anywhere.

Anyway if anyone has any ideas on what I should be looking for to fix this and have the OAR reading correctly that would be great!!!

Some side notes:
  • I’ve tried with meth turned off it reacts the same
  • plugs were changed 20,000km ago
  • multiple fillups 5+ from different gas stations with 94 so it’s not the gas
 

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Discussion Starter #3
What tune are you running? Try running stock tune and your oar should definitely adjust then.
Well it adjusts currently that’s the problem it’s adjusting the AOR very far to the positives. I am running the gearhead auto octane tune so AOR is left on with this tune.
 

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Well it adjusts currently that’s the problem it’s adjusting the AOR very far to the positives. I am running the gearhead auto octane tune so AOR is left on with this tune.
The problem is actually the tune. Part throttle mapping seems to not be well set up and dialed back from stock fooling the truck into thinking it has quality fuel. I had that problem with my 11 running that tune. At times when I clearly had inferior fuel like 87, the OAR was pinged at -0.96. Took that tune off a while ago as I was having the same problems as you. No longer had the problem. I was not alone on this problem. Don’t get me wrong it was a great tune but didn’t seem like much time was spent on 11-14 years tuning wise.
 

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The problem is actually the tune. Part throttle mapping seems to not be well set up and dialed back from stock fooling the truck into thinking it has quality fuel. I had that problem with my 11 running that tune. At times when I clearly had inferior fuel like 87, the OAR was pinged at -0.96. Took that tune off a while ago as I was having the same problems as you. No longer had the problem. I was not alone on this problem. Don’t get me wrong it was a great tune but didn’t seem like much time was spent on 11-14 years tuning wise.
Hm mine seems the opposite it seems to think it’s got garbage quality fuel and only whenever I drive it hard does it do it. It would be great in my case if it was reading good fuel atleast it would be so slow lol.
 

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...go back to stock tune and watch the oar. That will give you a more accurate reading of your gas quality. The Tune is tricking oar into thinking it’s high quality gas.
 

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...go back to stock tune and watch the oar. That will give you a more accurate reading of your gas quality. The Tune is tricking oar into thinking it’s high quality gas.
He's saying the opposite... that the OAR is increasing (indicating worse gas).
 

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Oar can be changed by the tuner on how it adjusts... just because they say they leave it on does not mean it’s set up the same as stock...
 

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Take it from me, mice make nests underneath the intake manifold if your truck has been sitting awhile. Underneath the intake is the 2 knock sensors. Had to replace mine after I got the truck because of this. Wires were chewed up, etc. Not saying this is your issue necessarily, but worth a look if your tune isn't an issue there. Mine ran like trash when I got on it too.
 

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Take it from me, mice make nests underneath the intake manifold if your truck has been sitting awhile. Underneath the intake is the 2 knock sensors. Had to replace mine after I got the truck because of this. Wires were chewed up, etc. Not saying this is your issue necessarily, but worth a look if your tune isn't an issue there. Mine ran like trash when I got on it too.
Here's a shot of my KS when I pulled them out. One wires chewed pretty good. Bunch of mouse nest crud on top of the sensors. Cant find the pics I had of that though.
 

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I would agree on going back to stock just to rule out any tune related issues, but i have never seen my GH tune go positive, ever. I have towed with it a bit and really put the wood to it an it always sat near -.9 with 91 octane. Never lower than -.8.

What is the Knock sensor reading? Is it going deep positive as well?
 

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Discussion Starter #13
I would agree on going back to stock just to rule out any tune related issues, but i have never seen my GH tune go positive, ever. I have towed with it a bit and really put the wood to it an it always sat near -.9 with 91 octane. Never lower than -.8.

What is the Knock sensor reading? Is it going deep positive as well?
Yep I am going to give stock a try today here and see if it fixes, it’ll be easy to tell right away!

Knock sensor ranges but the tuner shows the max it has hit is +7 which I imagine is not good!
 

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Put it back to stock, OAR settled at -0.64 and then never moved after that. I tried to drive hard on it and it seemed to have no effect.
However, when I tried putting it in manual mode and driving like that (downshifting etc.) then I was able to get OAR to go up to -0.24 where it seemed to stay then.

This sounding tune related or what you guys think?
 

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Put it back to stock, OAR settled at -0.64 and then never moved after that. I tried to drive hard on it and it seemed to have no effect.
However, when I tried putting it in manual mode and driving like that (downshifting etc.) then I was able to get OAR to go up to -0.24 where it seemed to stay then.

This sounding tune related or what you guys think?
I guess. It could be that there is something funky with the truck and the timing tables for the GH tune are more aggressive and so its a lot more apparent. IE, its having to pull more timing from the base tables because they are more advanced than stock.

The other thing to watch out for is that the stock tune turns of Knock retard above a certain rpm i believe. Ive noticed when I do a pull in my truck on the stock tune the KR will 0 out.
 

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Put it back to stock, OAR settled at -0.64 and then never moved after that. I tried to drive hard on it and it seemed to have no effect.
However, when I tried putting it in manual mode and driving like that (downshifting etc.) then I was able to get OAR to go up to -0.24 where it seemed to stay then.

This sounding tune related or what you guys think?
Oar will change when you’re at a certain load etc. Seems the way you are manual shifting you are forcing oar to change quite often? If you don’t mind me asking, why are you using manual mode in the first place?
 

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Discussion Starter #17
Oar will change when you’re at a certain load etc. Seems the way you are manual shifting you are forcing oar to change quite often? If you don’t mind me asking, why are you using manual mode in the first place?
In this case I was just using it to see if I could get the OAR to react the same as it was with the tune. Before using manual mode the OAR leveled out at -.64 like I was saying.

Daily I use it on the highway though which is 90% of my driving. I prefer it when passing instead of having to put it to the floor for it to downshift and go I can easily just drop a couple gears and pass.
 

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My truck has acted this way with certain tunes, particularly my variable octane tunes. My 5* performance tunes and my MPT performance tunes were also bad about doing that. OAR swinging all over the place. My performance tunes from Boostking and my tow tunes from 5* don't do it.

Sent from my Moto Z3 Play using Tapatalk
 

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Discussion Starter #19
My truck has acted this way with certain tunes, particularly my variable octane tunes. My 5* performance tunes and my MPT performance tunes were also bad about doing that. OAR swinging all over the place. My performance tunes from Boostking and my tow tunes from 5* don't do it.

Sent from my Moto Z3 Play using Tapatalk
Glad to know it’s not just the Gearhead tunes, did you ever find a resolution or cause for the issue?
 

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No I didn't, but my Gearhead tunes are the worst. My resolution was not running the tunes that do it. Lol.

I had one tuner desensitize the knock sensors in the area where the knock was occuring that would make the OAR get worse, since we determined it's most likely fasle. Interestingly, on a test revision he REMOVED timing where the knock spikes were occuring, and the knock got SUBSTANTIALLY worse (after that was when he desensitized the sensors there).

I still wasn't totally comfortable with that solution, and @Boostking was able to build me tunes that don't have the severe knock spikes occurring without cutting that corner.

I would LOVE to tear into it and insoect my knock sensor wires and replace the sensors, just to see if it helps. It's just too invasive though without knowing.

Sent from my Moto Z3 Play using Tapatalk
 
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