07/29/2026
I have a saying I adopted from a mentor years ago: "Cats don't die, they get murdered." It means your catalytic converter you just replaced didn't just go bad all on it's own. Something killed it.
If you're not finding the root cause of the failure, that nice expensive new converter you just put on your car is going to fail sooner than later. A good catalytic converter behind a properly-running engine should last several hundred thousand miles, full stop. When they scan the codes in your car and it says "P0420/P0430" it shouldn't be a green light to replace a converter. That's not diagnosing, that's a code scan.
This engine has been running rich, and while the failed converter isn't currently causing a restriction in the exhaust, it definitely needs to be replaced. The reason this engine is running rich is because the timing chain has so much slack in it that the crankshaft can rotate over 10° without moving the distributor rotor; while the ignition timing is correct, the spark plugs are brand new, the injectors have all been replaced, the fuel pressure is correct, and so on, this engine's mechanical valve timing is delayed. This causes the valves to open and close late, and sadly, the thousands of dollars that were already spent on this problem weren't needed.
While the picture doesn't look great, I'm pretty sure you can tell that this isn't what it's supposed to look like.
