O2 Sensor Help !!

[vincenza]

What are the signs when O 2 sensor is malfunctioning ?

Thanks again
Vinnie in Ventura
1989 911 Silver Anniversary

[ewave]

Disconnect it, see if the problem goes away. If it does.. chances are the O2 sensor is bad. :-)

[vincenza]

Dumb Question . Where is located in my car ?

Thanks

[Jeff]

The top of the catalytic converter.

[vincenza]

Thanks Jeff ,
will it damage my car to run it without the sensor?

Jeff is it Hot in AZ ?
It is 74 degrees in ventura and I have a sweater on in the office .

Thanks Again ,

Vince

[Jeff]

Vince it won't run as good. This is an input sensor for the DME/ fuel injection system. It tells the computer how rich or lean to make the gas / fuel mixture.

And yes it's HOT! I just fertilized my postage sized yard and am sweating my a$$ off.

[vincenza]

So Jeff ,
now I am confused . Ewave tells me to disconnect and if the problem goes away its the sensor . You tell me that if I disconnect the sensor the car will run bad anyway .


Vince

[Jeff]

Vince, the car won't run at it's optimal level without the O2 sensor. May run rich or lean at different load/ rpm ranges. I have heard of people testing their O2 sensors the way Ewave states but have never done it personally. The Bentley manual says to test the O2 sensor you need to use a pinout test harness at the DME and test fluctuations in voltage out put of the sensor.

[WydRyd]

The DME only relies on input from the O2 Sensor at Idle, or part throttle (<60% throttle). I believe with the O2 sensor in circuit, the DME aims to maintain a 14.x:1 A/F ratio at idle and part throttle.

If you disconnect the O2 sensor from the DME, it will richen the idle and part throttle mixture & adversely affect your mileage too.