O2 Sensor Problem...

Ok, so I have been having all kinds of stumbling on acceleration on
our 90 Civic and we have changed just about everything (timiing/valve
lash/timing belt/plugs/gap/plug wires/distributor cap/fuel filter/air
filter). People recommended to change the O2 sensor so we gave it a
go. Well what we noticed was that once we removed the old O2 sensor
and decided to drive it with out it connected, the car ran almost
PERFECT. No stumbling or studdering on acceleration now. PLugged the
old O2 sensor back in and it stumbled again. So we purchased a new O2
sensor from the dealer, expensive, and plugged it in. Absolutely no
difference, still stumbled. So our question is, it's obvious now that
the O2 sensor is fine yet our car still works much better without it.
Is this saying there is something else wrong?

Confused...

 

What's the mileage, and has other fuel made a difference?

'Curly'

 

you drove with the sensor unscrewed and an exposed hole there?

if so, and it ran better, you might have a clogged cat and it runs
better because the exhaust is escaping through that hole.

just a wild-ass guess...

would this make sense to anyone else out there???



PLugged the

 

yeah, i'd drop the cat & have a look. check the rest of the exhaust for
dents & constrictions while you're under there too.

 

On 2 Sep 2004 15:16:52 -0700, (djtech) wrote:

||Ok, so I have been having all kinds of stumbling on acceleration on
||our 90 Civic and we have changed just about everything (timiing/valve
||lash/timing belt/plugs/gap/plug wires/distributor cap/fuel filter/air
||filter). People recommended to change the O2 sensor so we gave it a
||go. Well what we noticed was that once we removed the old O2 sensor
||and decided to drive it with out it connected, the car ran almost
||PERFECT. No stumbling or studdering on acceleration now. PLugged the
||old O2 sensor back in and it stumbled again. So we purchased a new O2
||sensor from the dealer, expensive, and plugged it in. Absolutely no
||difference, still stumbled. So our question is, it's obvious now that
||the O2 sensor is fine yet our car still works much better without it.
||Is this saying there is something else wrong?

If you left the sensor in the hole, but disconnected the wire and it ran better:

Without a O2 signal most cars go full rich. If that helps the performance, that
could mean you have a vacuum leak.
Texas Parts Guy

 

210K Miles and use standard 87 octane fuel. Someone mentioned it
might be the throttle position sensor but then I thought why would the
TPS work better once the O2 was removed?

 

Im sorry, I should have said I just disconnected the wire to the O2
sensor, not actually took it out of the whole. Sorry about that.