Hello all. I will be doing a o2 upstream sensor change later on the back bank closer to the firewall and was wondering if I should just erase the computer codes or if I should disconnect the battery and hook terminals together to do a full reset and start it’s learning curve all over again. Currently I only have the one code for that sensor stored in the computer. Back bank I wouldn’t have to disconnect the battery in order to gain access so I was hoping I wouldn’t have to do that so I wouldn’t have to go and do all of the other relearns as in windows, sun roof, hvac among I’m sure others

 

Why not just disconnect the ECM fuse in the POWER DISTRIBUTION FUSE BOX?

The rest of the modules will be unaffected and the STFT, LTFT will be cleared. (all readiness tests will clear)

Can't help you with the fuse number because you do not specify a MODEL and YEAR.

bob

 

That would make more sense to just pull that fuse. I have back when I set up my details and sig line set up as 2002 (US) 3.0 base sedan but while viewing the forum from my cellphone that none of that info shows up when I make a post. Like for instance yours doesn’t show up for me either lol.

 

Tony, clearing the codes either way will do what you are after. Clearing out the ECU/ECM will help you determine if you still have a problem or not. The only "down side" to disconnecting the battery is that you will also have to reprogram the windows. Not a big deal. Takes a few minutes to do. Granted, that is an easy way to do things and you will probably spend 5 minutes trying to find the fuse. So, 5 minutes one way, 5 minutes the other.

 

Thanks Thermo and others. Got the sensor changed and I just deleted codes after install and went for a test drive and no light came back on. Stft and ltft’s are now reading and fuel system now goes into closed loop like it should. Now just to get these drive cycles completed. My state doesn’t do the smog or computer checks so the drive cycles can complete whenever conditions are right for it too. So for now happy motoring lol. Thanks again everyone

 

For your safety and the car I would disconnect the battery before working on it anyway there's very little room changing that sensor , that will then reset your ecm at the same time