Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Calibrations for FlashPro Manager - Use all calibrations at your own risk (dyno tuning recommended)

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aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

I just got a 8th Gen SI from a friend. Gotta admit that I am usually more geared into Nissans and Subarus. Also, my wife's Mazda CX-5 that I recently supercharged so I am fairly familiar with NisTune, AccessTuner, VersaTuner, and mazdaEdit. Hondata is pretty different than all of those and the VTEC is a whole new ballgame to me since it doesn't seem to mimic other styles of VVT. From what I can tell on this build:

K24A2 straight swap
OE injectors
OE intake manifold
J-bend SRI (pointed back at drivers seat)
Have yet to get under the car to look at the exhaust setup, but from the sound I am assuming it is NOT stock

It came with a FlashPro (but was running like complete and utter &#%@). When I loaded up Hondata it was running the basic OTS 8th gen SI map. From what I have gleaned from forum diving...it is able to run with that...just not well (understatement). During the forum diving I found @EFICU's map for someone running what looks like an identical build (viewtopic.php?p=122942) and used the base calibration. Already night and day difference, but still really rough. Hoping someone (@EFICU or otherwise) can help out!
EFICU
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Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by EFICU »

There is no link to the post for the calibration you are running, so give us more context on that or post the calibration so I can see which one you're running.

Also, posting a datalog would help see how it looks. When you say it's still rough, some elaboration there would be good. But a datalog is the main thing needed to see how it's running. If you got a similar basemap and it's still "rough", we would need to look at potential mechanical issues.
aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

My apologies, I thought the link was embedded. Attached is the Sir_Dartillian FPCAL viewtopic.php?p=122942 that I flashed. I will datalog tomorrow (can take a drive or let idle or whatever you need)
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Sir_Dartillian.SD.Rev01 (0Cam)(Vtec4500).fpcal
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aearynet
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Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

Ok, so previous statement after first driving was totally subjective. Now that I pulled a ~20 min datalog and have driven it a bit...it doesn't seem far off. Put it up on the lift and identified Buddy Club headers connected to the OEM exhaust. Datalog is attached!

@EFICU I definately welcome ALL input on this (as previously mentioned...kinda my first Honda build). Would also love to get familiar enough with HONDATA to start tuning myself.

Thanks in advance!
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08Si_Datalog1.fpdl
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aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

EFICU wrote: Mon Jun 13, 2022 8:36 pm There is no link to the post for the calibration you are running, so give us more context on that or post the calibration so I can see which one you're running.

Also, posting a datalog would help see how it looks. When you say it's still rough, some elaboration there would be good. But a datalog is the main thing needed to see how it's running. If you got a similar basemap and it's still "rough", we would need to look at potential mechanical issues.
I saw that the previous datalog I got didn't seem to contain much for some reason so I went ahead and relogged. I got one with "spirited" driving and then a slow and steady cruise with A/C on. Both labeled and attached.
Spirited_Datalog_06142022_01.fpdl
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SlowWithAC_Datalog_06142022_02.fpdl
(2.65 MiB) Downloaded 60 times
aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

Is anyone able to assist?
EFICU
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Joined: Mon Feb 25, 2019 10:14 pm

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by EFICU »

You have an issue with the primary o2 sensor. You need to address that before you can tune it. The ECU doesn't know what to do because of the error with the primary o2 sensor.
aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

EFICU wrote: Mon Jun 20, 2022 8:57 pm You have an issue with the primary o2 sensor. You need to address that before you can tune it. The ECU doesn't know what to do because of the error with the primary o2 sensor.
That was my next question actually, already have a replacement on the way as I didn't know if that was a known issue with a K24 swap or a normal mechanical issue (I forum dived a lot and saw conflicting information...so I erred on the side of getting a new one).

Apologies for the learning curve...kinda dove off the deep end when my first Honda setup ended up being a K-Swap lol

Will reply once swapped and verified no recurring DTC!
EFICU
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Joined: Mon Feb 25, 2019 10:14 pm

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by EFICU »

Yeah it's either a bad sensor, or you have a defouler on the primary o2 sensor. If there is a defouler on the primary o2 it will never get a proper reading. The primary o2 must be threaded into the exhaust stream with no spacer whatsoever. Don't beat on it in the meantime, the ECU has no idea what's going on and fuel trims are not being applied. Not to mention the WOT fueling is not ideal either.
aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

EFICU wrote: Mon Jun 20, 2022 9:11 pm Yeah it's either a bad sensor, or you have a defouler on the primary o2 sensor. If there is a defouler on the primary o2 it will never get a proper reading. The primary o2 must be threaded into the exhaust stream with no spacer whatsoever. Don't beat on it in the meantime, the ECU has no idea what's going on and fuel trims are not being applied. Not to mention the WOT fueling is not ideal either.
Is it fair to assume primary O2 is on the header primary tubes and secondary is on the test pipe?

Verified that the exhaust portion is:
- Buddy Club headers
- Test pipe (was leaking cause the catback was 3" bolted to a 2.5" flange without reducer...busted out the welder and a reducer so now its matched up and sealed with 3" flange to catback)
- 'FULLRACE' catback

There was a de-fouler on the test pipe that has now been removed and I am pending delivery of the replacement primary O2 for re-install.
aearynet
Posts: 8
Joined: Sat May 07, 2022 10:10 am

Re: Need help with my first 8th Gen SI K24A2 (EFICU...preemptive thanks a ton!)

Post by aearynet »

EFICU wrote: Mon Jun 20, 2022 9:11 pm Yeah it's either a bad sensor, or you have a defouler on the primary o2 sensor. If there is a defouler on the primary o2 it will never get a proper reading. The primary o2 must be threaded into the exhaust stream with no spacer whatsoever. Don't beat on it in the meantime, the ECU has no idea what's going on and fuel trims are not being applied. Not to mention the WOT fueling is not ideal either.
So, I swapped out the B1S1 O2 sensor with both a new Denso direct replacement as well as a Bosch Premium with no change. The DTC re-appears almost immediately after clearing. I also tested the old O2 sensor in a buddy's 8th gen and have had him driving around on it for a couple days and there is no CEL appearing nor any DTC in the history.

Checked the 4-pin connector for the B1S1 sensor and am not getting any short on the heater circuit wires and I also verified all fuses in the box are intact. Datalogging and Hondata display (laptop riding shotgun) do show the AFR readings changing as expected and I even did a quick autotune run and noticed definitely positive response on its adjustments even with the CEL still lit.

Any thoughts?
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