What are the symptons of a faulty Oxy Sensor Unit?

[Moke81]

Just did some work on my 1981SC valve adjust, MSD ignition new WUR. All pressures check out fine, no vaccum leaks.
Was running very strong then noticed a 20% or so loss of power cruising on the freeway at 3000 rpm in 5th. Putting my foot to the floor very slow acceleration. Then start ups when cold it would start backfiring, would not throttle up without pumping the pedal once it got a little warm it ran fine until hot then the loss of power would occur. Talking with a mechanic friend he said replace the oxy sensor relay.I did know difference. Then he said its the unit itself they are prone for going out over time when they do it goes into sort of a limp mode thats when the symptons occur.
Was wondering if these things have gone out for any of you?
_______
1981 SC

[johnsjmc]

I think your mechanic is thinking of a more modern injection system like the 84 and newer style.They are capable of going into open loop (limp home mode) The older K jetronic is quite different.I would replace the sensor itself before any relay or control unit . The SC system can run better without the sensor at all.Fuel mileage may suffer but You can disconnect the O2 sensor on your SC and set the mixture ratio manually at about 2.5%CO. Search O2 sensor removal on SC for more info

[emcon5]

Do your Dome lights work?

Tom

[Moke81]

the dome lights work

[Moke81]

I had the sensor disconnected, would that be the same as removing it?