Putting my 89 Colt GT (original turbo car) back together and running the original harness with original 4g61t ECU with DSMLink v2. I've noticed that my front O2 is not cycling at idle and have used 2 known good O2 sensors with no luck. Started doing some electrical troubleshooting today and got some weird results for pins 2 and 4 of the O2 sensor connector that should be grounding points. I know the chances of getting a volunteer to check this is probably slim to none, but I'll throw the request out there. If anyone could unplug their ECU and O2 sensor and check continuity between the 4 O2 sensor pins and the 3 ECU connectors and let me know their results, I would greatly appreciate it. I'll even send you some money for a six pack for your troubles