[GTP Dad]

Did you replace the cat.? This sounds like a clogged cat, you may want to check it but with 189K it is on borrowed time. Also change the fuel filter, you may be starving the engine for fuel if it is blocked, even though you were told it was replaced it may have plugged again. One other thing check the fuel pressure with a guage. The fuel pump may not be giving you enough pressure to keep the engine running properly.