What is the purpose of these, short of monitoring if the cats are working efficiently? From what I gather they dont alter any ECU parameters, only the pre-cat ones do. How true is this? I ask because I keep getting a 'high voltage' and a 'no activity' error, and these wont return for a little while after clearing them. I also get an error message that the heaters not working too, so I know the cats are working and the sensor is faulty. The voltages stays at a constant 0.4v while watching the live data.
Will it cause any issues leaving this for a little while?