don't know how it works with a tweecer,but I have lm-1 kit and you weld in bung in the exhaust and hook that up to the meter and then you can read your a/f ratios. If you're going to do it you might as well get the lm-1 kit with the rpm adapter so you can do the data logging and read your rpm's too along with the a/f ratio. I have the pms and together they work great.
Yes... you can use the LC-1 to data log with a TwEECer. It actually adapts better to the TwEECer than the LM-1 does. The LC-1 has 2 ea. scalable analog outputs that can be wired directly to one of the sensor inputs on the TwEECer at the EEC harness.
--or--
You can do the same thing the LM-1 guys (Me) do and that is to use the EGR position sensor wire to send that 5V output striaght to the TwEECer for data logging.