If the ECT had totally failed, the Ohms reading would be 32,000+. The normal reading on a cold engine is around 2800Ohms to 200Ohms for a hot engine. If the ECT fails to communicate to the ECU, then a P0nnn is set.

All you have is multiple misfires, and you need to crank the heck out of it to get rid of the gasoline that has washed your rings. While the ETM might be a problem, it usually sets its own error codes, you could have a loose or disconnected vacuum line or a loose air hose at the throttle body.

Any unmetered air entering the intake manifold will cause a rich condition due to the O2 sensors noticing a lean condition. The O2 sensors tell the ECU to increase the injector times.

Klaus
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Two good Volvos, a 220 and a V70R