My 1997 Ford Crown Vic with 267,500 miles might need a new cat. I'm not sure. I want to do an injector balance test first. I have till December before it needs to pass emissions so I've got time to figure it out. Originally it was throwing P0420 and P0430 codes, but I've gotten it to the point where it's only throwing a P0430 code. Yes, it has two cats, one of them is apparently OK now and the other still fails. I suspect that there's a fuel problem on the side with the cat that continues to fail, hence why I want to do an injector balance test. At least they're not buried under the intake manifold on this car, making them easy to unplug with the engine running.
I also need to install the new fender liner on the passenger side front. Someone apparently cut out a large chunk of the old one for who knows what reason. I have the new fender liner, just need to install it.
It also needs a new OBD-II socket. The one that's on it is worn out and makes intermittent connection with some scantools. Go figure. I have the parts. Mouser Electronics, by the way, carries a nice selection of Delphi/Packard connectors and terminals at good prices. 88 cents for the OBD-II socket connector shell and 20 cents each for the pins.
Finally, it may need a new pitman arm in the steering--there's about 1/8" of play in it.