After patching the rotted connection between the downpipe and cat on my NA 940 multiple times with Quicksteel (great stuff, BTW!) it's finally time for a completely new exhaust system - the whole thing is starting to fall apart, and is noisy as hell. Got everything I need from Eeuroparts, including new cat, downpipe and O2 sensor. The main question is, should I install the O2 sensor in one of the ports on the downpipe this time, instead of the one on the cat? As it's set up right now, the sensor is plugged into the cat just after the connection to the downpipe - so as soon as this connection weakens it lets air in just before the sensor and makes the car run rich, which has happened numerous times preceding my patch jobs. I figure if I move the sensor back to before this connection, I might have a noisy exhaust if the connection weakens, but at least the mixture shouldn't deteriorate as it has before.

Does anyone know if there could be a downside to doing this?

Thanks!