[Shotimes] Oxygen Sensor Question

[Donald Mallinson]

Several top mechanics, including a couple SHO experts that 
are widely respected have told me that O2 sensors are 
replaced way too often.  One told me that when they went 
bad, there would be little question as to something was 
wrong, but otherwise, they last a long time and 
deterioration has little to do with how the engine runs.

Bosch would have us believe that we need them quite often of 
course.  I still have the original sensors in my '89 at 
180,000+ miles.

My son had some issues with his 95 ATX, and wound up 
replacing both sensors, but it didn't really solve all the 
problems.

Don Mallinson

Leigh Smith wrote:
> Someone correct me if I'm wrong, but I'm under the impression O2 sensors are
> changed much more often than necessary. An aged sensor should have almost no
> effect on steady state cruise, or emmisions, unless poisioned or obviously
> broken (codes). (My 280K SHO still passed NJ emissions with original cats
> and original O2 sensors and 28mpg)
> Has anyone ever had new O2 sensors change emissions or increase gas mileage?
> Where the sensor had not obviously failed(codes)?
> The impression I'm under is that an aged but not yet failed O2 sensor would
> cause a part throtlle "power" application to go very slightly lean, possibly
> affecting power and mileage. But how much? Noticably?
> Anybody confirm this?
> Lee