AEM Fail Safe using Rear O2, Anyone done this?

[Cross]

Originally Posted by welllam

Make sure you connect the aem output ground as well to get the correct reading.

And how I mount it

That's how I did mine as well and I will go double check that maybe it came loose that would be a quick fix and explanation.

[protpibe]

Originally Posted by BRZGM3

So I just ordered the AEM fail safe A/F and I'm curious where some of the other members have mounted them in their interior?? I already have the p3cars gauge in my vent so that option won't work. Any help, maybe even pictures would be great. Thanks guys

[Cross]

@welllam got it right, the ground had pulled back apparently during install from the grounding point I used under the dash for it (The brown analog wire from the AEM) and that seemed to be causing the issue.

However it is a full point off. AEM reads 18.0 and EcuTek reads 17.0. I guess that's a lot better but it is still strange. Granted I did this test with the car off just checking the connection and watching the results based off the air already in the exhaust. Perhaps this will change once I am driving I will test it shortly.

Thanks again Welllam that was a good idea to recheck that ground.

[Kodename47]

Originally Posted by Cross

However it is a full point off. AEM reads 18.0 and EcuTek reads 17.0. I guess that's a lot better but it is still strange. Granted I did this test with the car off just checking the connection and watching the results based off the air already in the exhaust. Perhaps this will change once I am driving I will test it shortly.

You have to setup the input on the ECU for ECUtek, my guess is that it's not quite calibrated correctly.

[King Tut]

You are feeding the signal into the rear O2 sensor and not the primary O2 sensor right? Only the primary O2 sensor is utilized by the ECU for closed loop operation by default. You then need custom RaceROM tables to make use of the more accurate wideband signal you are now feeding into the rear O2 sensor input.

[protpibe]

For you guys using the AEM failsafe, how would you setup the alarm trigger for a certain boost level?

I was playing around with it this morning and it looks like the alarm trigger is based on an AFR table VS Boost. I want the alarm to go off at 12psi and above so I set the trigger to be any AFR level above 6:1 at 12PSI+ effectively making anything over 12psi the trigger. Is that a complicated way of doing it, and did I miss something simple?

[King Tut]

Originally Posted by protpibe

For you guys using the AEM failsafe, how would you setup the alarm trigger for a certain boost level?

I was playing around with it this morning and it looks like the alarm trigger is based on an AFR table VS Boost. I want the alarm to go off at 12psi and above so I set the trigger to be any AFR level above 6:1 at 12PSI+ effectively making anything over 12psi the trigger. Is that a complicated way of doing it, and did I miss something simple?

That is the correct way to do it. I wish there was more adjustability like maybe bringing the RPM input into it, but there isn't. All you can do is move those dots on the graph up or down and mess with the delay settings.

[Cross]

Originally Posted by King Tut

You are feeding the signal into the rear O2 sensor and not the primary O2 sensor right? Only the primary O2 sensor is utilized by the ECU for closed loop operation by default. You then need custom RaceROM tables to make use of the more accurate wideband signal you are now feeding into the rear O2 sensor input.

Yes this is the rear O2 the front O2 is still connected and being used but apparently the rear reading 20-21 was enough to try and bias the tune and cause issues. I expected it to just be an input and any ability to effect fuel trims removed but it seems otherwise.

I am waiting to hear from Mike on fixing the AFR being off 1 point it actually got closer with driving but it is still off by at least .5. I was already late to work this morning messing with it so I will check things later.

I always seem to have the weirdest luck...

[OjiGeorge]

I've connected my AEM Uego to the 2nd O2 sensor wire going to the ECU, but still need to get RR7 on my car.

Due to not having RR7, I get a check engine light every time I drive the car. Obviously, the info being provided from the wideband to the ECU's secondary O2 sensor isn't doing much good yet. That said, hoping it will help with dyno tuning so I can run an AFR >9 when WOT.

[welllam]

Originally Posted by OjiGeorge

I've connected my AEM Uego to the 2nd O2 sensor wire going to the ECU, but still need to get RR7 on my car.

Due to not having RR7, I get a check engine light every time I drive the car. Obviously, the info being provided from the wideband to the ECU's secondary O2 sensor isn't doing much good yet. That said, hoping it will help with dyno tuning so I can run an AFR >9 when WOT.

What cel code are you getting? If you don't connect the output ground of the aem then you will get the error code of voltage exceed max value.

Mine is also off. Mine is off by 0.8 at lift off, IE 18 at gauge vs 17.14 at log. But I am still not sure how to calculate this error mathematically to compensate the error because it isn't a direct calculation. It is in fact quite dangerous because Ecutek logged 10.5 afr but the gauge read 11.9.

So far only sportguy83 got a very close value between gauge and log.


我從使用 Tapatalk 的 SM-N9005 發送

[Cross]

For me it is causing serious drive-ability issues. Mine is also about .8 off and Mike has not made any changes to that yet.

Mine also like to try and die now at stop lights when you first hit the gas, rpm's go down to 400 or less then come back up.
Then while cruising timing is jumping all over as is afr, just cruising at say 40mph. 11-16afr just putting along. It's annoy and frustrating because it does it the more you drive. Mike thought it was LTFT and shut that off, it did nothing to fix it. For me driving it has become an exercise in hitting the gas before the light turns green to handle the dip and dealing with my car basically feeling like it is fighting me.

But all of this goes away if I disconnect the signal wire to the Ecu.... screams to me that no matter what the Ecu is making adjustments based off that signal and considering mine is not matching the factory front O2 the Ecu just seems to be fighting with itself and making me not want to drive my car.

[Kodename47]

Originally Posted by welllam

Mine is also off. Mine is off by 0.8 at lift off, IE 18 at gauge vs 17.14 at log.

At lift off you'll be at maximum AFR on whatever you're looking at as there is no combustion/fuel injected. It looks like the OEM sensor is limited to 17.14 then and the WBO2 is 18. Either way, neither matters.

Yes, the rear O2 sensor does make a difference, there is a setting to try and turn that off. It won't be that they don't match, more so that the ECU is expecting a voltage for the OEM rear sensor. You're still triggering whatever it is that the OEM rear sensor does when your WBO2 outputs voltages that the ECU doesn't like.

[xjohnx]

Originally Posted by welllam

What cel code are you getting? If you don't connect the output ground of the aem then you will get the error code of voltage exceed max value.

Mine is also off. Mine is off by 0.8 at lift off, IE 18 at gauge vs 17.14 at log. But I am still not sure how to calculate this error mathematically to compensate the error because it isn't a direct calculation. It is in fact quite dangerous because Ecutek logged 10.5 afr but the gauge read 11.9.

So far only sportguy83 got a very close value between gauge and log.


我從使用 Tapatalk 的 SM-N9005 發送

@moto-mike had to tweak the scaling for mine as well. log your rear o2 sensor voltage and make a table correlating the voltage to what your AEM gauge is displaying. That should help your tuner dial it in.

[Reaper]

@Cross I pm'ed you and didn't get a response, do you still need those parts from me? if not just let me know.