I've got a 1990 355 tpi with 730 ECM while running Datamaster I get all data except O2 voltage (stays at 450 mlv),and the BLM never changes (128). I had a 4 wire O2 (GM) installed in my headers. So I replaced it with a AC Delco 3 wire and still no data. Checked connection from O2 to the ECM is good. ON the ALDL web site it shows data going to two pins on the ALDL connector under the dash,(pin m and e). I have pin M connected. I'm I missing something? My wideband is working fine, is there a way to control the ECM with the wideband? I'd rather get the ECM to use the OEM NB O2. anybody have an idea what the problem is ? any help please thank you Mike