O2 Sensor, what to buy? Options

[bbrock]

First, apologies because I know this has been covered somewhere but both local and Google search have failed me.

I'm heading to uncharted waters. All I know about O2 sensors are they are handy for measure A/F for tuning carbs and where to mount the bung. I have no clue about what is a good affordable sensor to buy for tuning a set of 40IDF Webers for a 2.0L engine. Don't even know whether wide band or narrow band is best. Just clueless really. Help Please!

[914Toy]

My O2 air/fuel mixture metering system experience in my 2.7L 911 engine with carbs, is as follows:

1. I have INNOVATE's double channel DLG-1 model that includes two O2 sensors, one in each exhaust header, some 4" downstream from the header pipes' converging point.

2. They supplied two Bosch model LSU 4.9 O2 sensors (P/N 3890 - 3' harness), and two 1" long bungs. These bungs place the sensor in the correct position, where as the typical 1/2" bung places the sensor too far into the gas flow, resulting in a short life of the sensor (ask me how I know!).

3. This kit's harness is long enough to install the gauge in the dash.

4. I have been on a long learning curve installing and tuning my carbs. I believe my carbs are optimally tuned which would not have been possible without; a) Paul Bennett's excellent information (Performance Oriented), and 2) INNOVATE's O2 air/fuel metering system.

5. Being able to monitor air/fuel mixtures while adjusting the carbs and driving the car, teaches one a lot about the consequences of changing various fuel and air jet sizes and adjusting air/ fuel mixture screws.

6. This journey was a lot of fun, and I agree with Mark that once installing and tuning carbs is complete this air/fuel ratio info declines in value. However, the continuous air/fuel ratio monitoring info is there in my dash and satisfies my "tech" instincts.