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Lamda voltage issues/alternator

Posted: Wed Oct 08, 2025 4:14 pm
by 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

Re: Lamda voltage issues/alternator

Posted: Thu Oct 09, 2025 9:00 am
by Spunkster
Once the alternator is replaced, see if the issue is resolved.

Re: Lamda voltage issues/alternator

Posted: Thu Oct 16, 2025 12:56 pm
by MadVTI
I am having a similar issue

Re: Lamda voltage issues/alternator

Posted: Thu Nov 27, 2025 7:41 pm
by 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.

Re: Lamda voltage issues/alternator

Posted: Fri Nov 28, 2025 2:36 pm
by 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?

Re: Lamda voltage issues/alternator

Posted: Sun Nov 30, 2025 2:44 pm
by Broscheslide
I changed the analog to d10 and it’s better but I still get an erratic lambda voltage. Jumps .2-.5 volts.

Re: Lamda voltage issues/alternator

Posted: Mon Dec 01, 2025 3:03 pm
by Spunkster
Do you have aftermarket injectors?

Did you set the dead times correctly?