[dekr]

I replaced the O2 sensor back in June, but then I Nuttered it in July. Doesn't the bypass render the O2 sensor useless? It started this about three weeks ago, but maybe the Nutter caused it and I just didn't notice until the cold hit.

No major coolant or oil leaks, and the plugs were changed last week.

It's not a big deal and doesn't affect performance in any way after a few minutes of warming up. I'm just curious and hoping it isn't a prelude to some major mechanical breakdown on the horizon.

Anyway, thanks for the tips!