Looks like it is running lean at idle, or thinks it is, scoping front lambda sensor at idle after resetting trims to zero should show as a low voltage and not switching,if a fault does exist.

Check for exhaust leaks or cracks near the lambda sensor, could be pulling air back in. I normally spray round with choke n carb cleaner while watching the lambda sensor output.
Could still have a faulty cat, but need to fix the trim error first