loosened the heat shroud round the cat. Well, haven't found the short
yet but at least I can drive now !!!!! I assume it's O.K. to run the
oxygen sensor without the heater, just a bit rich on startup ?
The O2 sensor *really* wants to run *hot*, and depends on the heater
to do so (the 3-wire sensors "last longer, 'cuz they're not exposed to
the brutal heat load next to the engine like the 1-wire units", so saith
my mechanic), probably not a problem at sustained 80mph, but puttering
around it will cool off *way too much* and you will definitely be running
rich, and fail any emissions test . . . (startup, the O2 isn't working
anyways, you're running open-loop for many seconds minimum, several
minutes if really cold and you just idle/warmup your engine). I think
your biggest problem would be fouling the plugs and/or O2 sensor (and/or
the Cat too) if you run too rich too long (Sorry officer, but I *have*
to drive at least 80 to keep the O2 sensor up to temp so I don't ruin
the Cat and pollute...Honest...[if it works, lemme know!])
Um, I assume this O2 is located back by the Cat, right? 3-wire unit?
In my UrQ, with the non-heated one-wire O2 sensor located up front just
downstream of the turbo, I can see (gas analyzer) the mixture noticeably
worsen during just a minute of idling, and rapidly improve with just a
few seconds of 3000rpm to heat the sensor back up...