Erratic AFR - Maybe not a Kpro issue?

[AngryScottish]

Vehicle: Noble M400
Kpro Serial: 47206
Software: V4.5.1
ECU: 37820-PPA-A07; 2828-106215 OF15
Kmanager: V4.5.1
I have an AEM CD7DL dash, that gets a CAN output from KPro.


What happened prior to main issue:
Been experiencing a weird hesitation that has been inconsistent -- AFRs would jump erratically then return back to normal like nothing happened.

Related, but a side issue, I connected my laptop to the ECU. Sometimes KPro won't output to the dash with my laptop connected, and the readout on the laptop is very slow. I disconnected the laptop, cycled the ignition, then the engine wouldn't run. Would crank over, but wouldn't fire.
After about 20 minutes of waiting, and uploading older maps, engine sprang to life.

Drove home, even WOT, and ran fine.

Today, datalogged an issue where the AFRs were going nuts, with the throttle consistent, RPMs fairly consistent. Attached is that datalog.


Questions:
- Could this be a dirty injector / fuel pump?
- Could this be the beginning of a faulty wideband?
- Would KPro indicate a random misfire event for a bad coil... ?

[TTR]

What wideband are you using? The S.Trim is all over. A/F goes rich at 4.5 seconds, so either it needs tuning or the wideband is on its way out.

[AngryScottish]

It's whatever PLX was selling with their wideband setups. They claim "Bosch LSU4.9 oxygen sensor"

I just flushed my injectors, they seem fine.

Still curious if Kpro logs misfire events,

[atlex]

the Ign and MAP definitely don't correlate to the AFR, I can only suggest interference or failure of the sensor.

You're in closed loop in that part - I can see the S trim chasing the peculiar AFRs, I'd go open loop and see how it behaves then.

If you have another car with a 4.9 LSU unit, swap them around and see how that behaves too. (I have 3 cars on this unit.. heh, I assume the Noble isn't your only car!)