Lamda voltage issues/alternator

[Broscheslide]

Can a failing alternator cause the lambda voltage to behave erratically? Cars tuned professionally. Been driving it for a year now. Noticed the lambda voltage wasn’t steady. Afr on aem gauge is fine. Had my alternator tested. Failed. Gonna replace it, just wanted to see if something else could be the issue

[Spunkster]

Once the alternator is replaced, see if the issue is resolved.

[MadVTI]

I am having a similar issue

[Broscheslide]

Changed the alternator. Same issue. Car will be idling and the lambda voltage will be steady at idle. Then randomly it’ll start going erratic. Can’t even read a steady voltage. Gauge is steady. I’m gonna take a look at my ground and wiring.

[Broscheslide]

I’m thinking it’s a grounding issue. It’s a aem uego wideband. Should the gauge main ground be to battery or thermostat and the analog ground to the analog ground in the hondata or on thermostat?

[Broscheslide]

I changed the analog to d10 and it’s better but I still get an erratic lambda voltage. Jumps .2-.5 volts.

[Spunkster]

Do you have aftermarket injectors?

Did you set the dead times correctly?

[Broscheslide]

So I’m still having this issue. Idk even know if it’s an issue. I’m closed loop, should lambda voltage be steady or is it normal to fluctuate .2volts back and forth rapidly. Car idles fine drives fine but when at idle the voltage fluctuates between 3-3.2 volts at a rapid pace. Short term trim is under 5 percent.

[Spunkster]

Without datalog it's hard to say.

[Broscheslide]

heres a datalog

lambda voltage.s3d

[Spunkster]

looks pretty normal