B16B crower 402-2 cams, stock inj, intake, exhaust, 95 RON - going lean at WOT

[aqeelrizni]

It's my first Hondata experience and still learning, appreciate any support

So I've tuned the car on open loop for low fuel maps, car runs fine.
I switched to close loop and began to tune my high fuel map. On 4th gear if i go WOT at around 4500 and before the vtec switchover point (vtec is at 5200), car begins to lean out (16-19 AFR) and stutter/hesitate and I let off. Only happens on the 3rd, 4th, 5th gear. From a pull 1-2-3 gear no issues.

1. It's been asked many times, and I've tried the different settings for the voltage/lamba and offset tables (AEM x series UEGO) - I have tried D10 and D14 on settings i read online. Any other settings i could try.

2. Is the leaning out at WOT, due to any fuel pressure related issue? Or map sensor related?

Attaching my log and map if anyone can take a look.

[Spunkster]

The datalog does not appear to show going WOT at any point.

[kraquepype]

You will need to figure out your wideband before continuing any tuning. Your voltage offset is huge - make sure your +12v signal is good and the ground is the same as the ECU (thermostat housing ground). I have a PLX and adjusted it slightly to get the hondata AFR to match up with what the PLX gauge was showing, but it should not be much more than a 0.1v/-0.1v offset.

Most documentation I've seen call for the wideband to be wired to the 12v at the ECU, but I found that the current draw at startup (sensor warmup) was an issue and ran it to a separate 12v source.

Using D10 requires removal of resistors and disabling ELD, D14 is the stock O2 input, it works but is limited in voltage and you lose the option to use the stock sensor for closed loop. D12 is an additional input on the ECU and you get to keep your narrowband and ELD - I can't remember offhand if it requires any modification to use though.

Regarding leaning out at WOT, it sounds like closed loop is causing it to go lean, but the datalog shows closed loop is off. Was the posted calibration the one used when you noticed the issue?

[aqeelrizni]

thanks @spunkster @kraquepype
you're right i need to re-check my wideband wiring to sort that voltage offset. And i think i resolved the leaning out issue.
Iit seemed that my closed loop (wideband voltage) was what was causing this issue. I re-started a fresh calibration and after tuning open cruising and partial load, switched to closed loop (narrowband) and car seems to run fine now.