Yes, mine is not a CarChip Pro product at all. It's a different brand of OBD2 sensor, of which Amazon had at least a dozen. It doesn't connect to the computer, and I don't think it can be used while the car is running.
But at this point I'm really sure it's the catalytic converters. (I know you're not sure, but you take an inordinate amount of evidence to be sure, and I am sure enough to meet my threshold.
) The really good news is that I successfully ordered compatible parts online myself, and plthijinx is
completely. awesome. and is going to install them for me, with the help of a friend and a welding torch.