Repair or replace 2001 toyota sienna 194,500 miles

The good, the bad and the ugly -GOOD: this van has had it’s timing chain (?belt) replaced about 20,000 miles ago, good brakes, new spark plugs, new catalytic converter, good tires, the bad: window on driver’s side doesn’t go up and down, the UGLY- BIG QUESTION: the check engine light is on because the O2 sensors need to be replaced. Is the van worth this next $500 repair? The dash board is like a disco- the passenger seat unbuckled light won’t go off, the check tire pressure comes and goes, and now the constant check engine light is on. I’ve covered all the lights up with black duck tape for piece of mind, but really? what should I do next? Gas mileage sucks! On the other hand, without the seats, it’s the perfect bread transporting vehicle for my new bakery.

Sounds like the van’s worth fixing.
Oxygen sensors are a common failure item and shouldn’t set you back more than a few bills to replace.
Power window problems are not uncommon (regulators and switches sometimes fail), but are usually easy enough to diagnose and repair.
Have your shop figure out which TPMS tire pressure sensor is causing the light. Maybe you ran over a nail. One or more of the TPMS batteries may be weak.
Oxygen sensors have an effect on fuel economy.
Do you have the 1MZ-FE 3.0 engine? Those engines are pretty tough, if you keep up with the maintenance.
You may have a bad seat buckle switch . . .
Did a shop quote you $500 for one/both of the repairs?