But remember, if there is excessive fuel being dumped into a cat, it is possible to overload the cat and leave deposits across the combs. If these deposits never burn off in the future, then the cat would effectively have less useable surface area to combat pollutants.
You would be just fine removing the cat to see how it runs, if this is a concern. A simple compression check will yield the data we are after here.
Even if the cat was plugged and an exhaust valve had yet to burn or warp, the engine would be running just fine, which it's not..
