Roger A. Ellis

The instructions say to disconnect the battery.
What happens if we don't disconnect it?
Thanks.

Ede's 12v90

the ecu doesn't reset

Jestapilot

I'm guessing that it will take a much longer time for the ECU to adapt

rtking

...but it will eventually settle-out. The only problem is that your ECU will be unlearning what it knew before and will have to relearn again. By unplugging the negative terminal, you wipe-clean what the ECU has learned and you can see what effect the O-rings have on your sensors without having your results skewed by any previous CELs or issues you may have experienced.

Bob

VAP

way to go Bob! Great answer. Couldn't have said it better.