Bye Bye O2
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
Likes: 26
From: Houston, Texas
Bye Bye O2 Had my tuner delete my O2 sensors, I'm running it Open Loop with the MAF. He had previously dialed in AFR on his dyno. All I got to say is what a world of difference, My O2 sensors kept dying in my long tubes (I'm guessing rain or not hot enough car is a daily driver) and the car would run rich. Such a pain in the *** changing sensors out all the time. Well no more! Engine runs smooth as silk now. When I upgrade my intake manifold here in the coming months I will go full OLSD tune at that time. Man those O2's were a pain in the ***.
Car is LS1 SBE, TFS as cast milled to 61cc BTR bowel blended, 232/236 .600"/.600" 114 +4 advance, LS6 intake stock TB, LT to true duals. If you have a good tuner and problems with your O2 sensors I recommend trying this route. Pat G tuned my car and its nice to have it running hard again. Feels like I picked up RWHP getting rid of the rich condition.
Just sharing......
Car is LS1 SBE, TFS as cast milled to 61cc BTR bowel blended, 232/236 .600"/.600" 114 +4 advance, LS6 intake stock TB, LT to true duals. If you have a good tuner and problems with your O2 sensors I recommend trying this route. Pat G tuned my car and its nice to have it running hard again. Feels like I picked up RWHP getting rid of the rich condition.
Just sharing......
No reason that cam should have killed O2's with a proper tune. A hybrid OLMAF setup would have worked just fine. Essentially you're open loop at idle and closed loop say above 1500 rpms where you have enough heat and exhaust flow to accurately measure with the NB02's.
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
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From: Houston, Texas
Do you see any issue with running it like this?? Or have you experienced failing O2's?? I tried Bosch 13111, and Denso all seemed to last up until maybe 1 or 2 big rain storms.
Side note when my car was bolt-ons only I had the same issues with O2 sensors.
Bosch 13111 aren't very good O2s. Most go denso or ngk and have better luck. Yes I've ran into the issue where it adds fuel as have many others. The solution is to have a hybrid tune instead of full time open loop. There's nothing to account for changes in weather any longer with full time OL. Being in TX it's better than up north, but it could have been solved another way. Also there's a thread on here where people swapping the wiring of the PCM so the rears are the front and it supposedly solved their issues.
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
Likes: 26
From: Houston, Texas
Bosch 13111 aren't very good O2s. Most go denso or ngk and have better luck. Yes I've ran into the issue where it adds fuel as have many others. The solution is to have a hybrid tune instead of full time open loop. There's nothing to account for changes in weather any longer with full time OL. Being in TX it's better than up north, but it could have been solved another way. Also there's a thread on here where people swapping the wiring of the PCM so the rears are the front and it supposedly solved their issues.
Having a temp compensation curve can help, but since a tuner can't tune the car during all different weather extremes they are using a best guess. The fuel trims are there to account for this error. It's also not just air temp but also air density as well that can vary.
i have a cammed long tube set up. yeah if i leave all the trims on before the VE is tuned it wants to go pig rich and foul the NBO2's.
solution of course is to tune it without trims on and then mess with the switching voltage until they don't roll over into pig rich all the time.
hard to imagine doing it remotely though. I'd probably do a OLSD on that and just send it.
solution of course is to tune it without trims on and then mess with the switching voltage until they don't roll over into pig rich all the time.
hard to imagine doing it remotely though. I'd probably do a OLSD on that and just send it.
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TECH Apprentice
Joined: Sep 2016
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So, I agree. It's not so easy to kill o2's.
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
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From: Houston, Texas
His comment to me was, I feel comfortable turning your car into an open loop tune that ignores the O2 sensors since it was already tuned on his dyno using the wideband. Perhaps he did some of the things you are suggesting? He is quite a reputable tuner.
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
I can see running a good OL tune, but still run O2's for minor corrections, IE not letting O2's do too much corrective work.
I think most good tuners, well if not all tuners shut off LTFT's with a cammed car, especially boosted.
If your tuner is relying on the LTFT to compensate for a shitty tune....well you need a new tuner.
Yes I know some people run completely OLSD or dare I say OLMAF tunes....
IMO, there is no way to account for everything. Let the PCM take care of some of it.
I understand if you run OL at idle(depending on the PCM)to compensate for a cam with huge overlap were the 02's are freaking out.
The few tunes that I have seen where they run OL all the time is because the injector data they have is garbage or the injectors themselves are garbage.
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
Likes: 26
From: Houston, Texas
Just from driving it around, and to be honest its probably just throttle response that I'm feeling, before the rich car was bog master and throttle felt laggy now its takes off, rpm seems smoother seems to rev faster. I also did plugs and wires with the tune, looked at my old plugs they had a bit of carbon build up on them, looked a bit rich, but I only ran those plugs 5k miles TR6 gapped at .040.
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
Likes: 26
From: Houston, Texas
I think most good tuners, well if not all tuners shut off LTFT's with a cammed car, especially boosted.
If your tuner is relying on the LTFT to compensate for a shitty tune....well you need a new tuner.
Yes I know some people run completely OLSD or dare I say OLMAF tunes....
IMO, there is no way to account for everything. Let the PCM take care of some of it.
I understand if you run OL at idle(depending on the PCM)to compensate for a cam with huge overlap were the 02's are freaking out.
The few tunes that I have seen where they run OL all the time is because the injector data they have is garbage or the injectors themselves are garbage.
If your tuner is relying on the LTFT to compensate for a shitty tune....well you need a new tuner.
Yes I know some people run completely OLSD or dare I say OLMAF tunes....
IMO, there is no way to account for everything. Let the PCM take care of some of it.
I understand if you run OL at idle(depending on the PCM)to compensate for a cam with huge overlap were the 02's are freaking out.
The few tunes that I have seen where they run OL all the time is because the injector data they have is garbage or the injectors themselves are garbage.
Side note is it true that the older Gen 3 PCM struggles more with the O2 data? That's what in my car.
Thanks for the discussion guys.