P1788 and P0430 Diagnostic Issues in 2002 Lincoln LS V6 with Catalytic Converter and O2 Sensor Problems

My 2002 Lincoln LS V6 is exhibiting several troubling symptoms. When accelerating, the vehicle struggles to climb hills—reaching 3000 RPMs only yields about 30 mph. The car also idles poorly in cold weather and occasionally shuts off during idle. When the engine is warm and idling, I detect a faint exhaust odor inside the cabin. During rapid acceleration for passing, the check engine light flashes until I turn the vehicle off. Additionally, my instrument panel no longer displays the current gear—instead, it shows 'E', which appears to indicate a transmission error. A visit to a transmission shop revealed that the car does not skip gears as previously thought, but rather shifts roughly. I do not have a P0420 code, yet the symptoms of power loss strongly suggest issues with either the catalytic converter or the oxygen sensor (low bank 2—P0430). My vehicle has 217,000 miles and I'm wondering whether repairing these components is worth it. I have already replaced the power steering pump, serpentine belt, battery, and two alternators (including a brand-new one used for two years). The P1788 code indicates an open circuit in the ECM signal related to the 3-2 timing or coast clutch solenoid—specifically, pressure solenoid B. The P0430 code points to low catalytic converter efficiency on bank 2. Given these symptoms and codes, I suspect both a failing catalytic converter and an engine misfire are contributing factors.