Toyota Repair: TPI Catalytic converter or ????, clogged catalytic converter, toyota 4wd

Question
My 93 Toyota 4WD 22RE 4cylinder is running poorly,
Lack of acceleration, poor fuel mileage, and rough idle.

This is a basic 4WD, NO A/C , but does have EFI

I have replaced the fuel filter, plugs, wires, cap & rotor.

This seems to run worse, and idle irradic when weather is hot.


I know for a fact my exhaust is in need of replacement, but I am unsure if I should focus my attention on a possible bad TPI Sensor, or could these symptoms be caused by a clogged catalytic converter, or possibly something else? Parts are rather expensive, and I cant afford guessing.

Sure would appreciate your expertise.

Thanks

Answer
I don't think the TPS is the cause of the problem, it would turn the check engine light on, the first thing you should do is to make sure that the engine cylinder compression is good, it should be around 160-180 psi +/- 10 psi. Doing this will eliminate a possible internal compression leak if the compression is good, if there is a low reading, 90psi or lower on one or more cylinders there is an internal leak, the most likely cause is a leaking valve or a blown headgasket, so do this first, this will give you an idea of what shape the engine is in and then get back to me.