Sensor problem 633csi

1981 633csi when engine is running light on test panel ( O2 sensor) stay on. I guess it needs replacing Does anyone have photos of this engine with the location of the sensor any help would be appreciated. Thank You Bill. G. Engine seems to run strong

The sensor screws into the exhaust pipe just to the rear of engine on my 81 633. The wire then runs up to connection on passenger side fender well in the engine compartment. Very easy to remove and replace but be sure and get one piece original BMW not aftermarket. Both are Bosch but the aftermarket is a universal and you have to be VERY careful to cut the wire the correct length. They are basically measuring resistance so length is critical. You WILL notice a performance differance after you replace a bad O2 sensor.

The sensor screws into the exhaust pipe just to the rear of engine on my 81 633. The wire then runs up to connection on passenger side fender well in the engine compartment. Very easy to remove and replace but be sure and get one piece original BMW not aftermarket. Both are Bosch but the aftermarket is a universal and you have to be VERY careful to cut the wire the correct length. They are basically measuring resistance so length is critical. You WILL notice a performance differance after you replace a bad O2 sensor.
Thanks for your info. Next dumb question I have is. Do you or any one know what wheels would fit this csi ? I am looking for 17" aftermarket or take offs from anyother car. Thanks again