I am wanting to know how to tell if it is the cat overheating or if the ECU for the cats is off. I have heard that a lot of 348s have 1-4/5-8 lights come and then the car will drop to 4 cylinders. My main question is if this happens I have heard that if you cats are ok and it isn't there that you can unplug the sensor at the ECU (2 of them right?) and the car will go back to all 8 but however if it is an overheating cat then the car could catch on fire. What is the best way to tell if it is an ECU malfunction or serious issue? Thanks.