Toyota Repair: 92 toyota truck, vacuum leaks, intake leaks

Question
hi;

i have a 1992 toyota truck, extra cab, 2WD, V-6 engine, 3.0 liter, 5 speed transmission.

the problem i am having is on the engine. it has poor driveability, intermittent power hesitation, gas mileage is poor. the engine hesitates, and sometimes, does not seems to "speed-up", (boggs down), or does not pull anymore power, around 2500+ RPM or so, just like it is lacking either fuel, or air.

i reasontly had a complete cylinder head job done on it, did it myself, because of a burnt valve. truck engine has: a new MAF sensor, TPS sensor, catalytic converter, oxygen sensor is original for now, fuel injectors ohmed out good. no vacuum leaks, intake leaks, etc... the rest of the other engine parts are all original.

i have not had a chance to check the fuel pump, fuel regulator for pressure, i don't have a tool for it.

the timing is correct, as i have done the timing belt three times on the engine. spark plugs are new, cap & rotor are also new, plug wires are about three years old. the engine has original 158,000 miles on it.

i never had a problem with the truck until i got it back from a toyota dealer, after they did work on a "recall on the head gasket" on the engine. they said i needed around $2900.00 engine repair on the truck, because of a burnt valves. that is one reason i decline for the dealer to do the work themselves, it cost too much, and so i did the heads myself..., with the help of a OEM toyota manual.

i had a friend said that it might be the ignition coil, but it ohmed out good also.

thanx for your time and please let me know what might be the problem...

aloha;
phil  

Answer
It sounds like there may be a problem with the catalityc converter, it may be disintegrating and getting clogged up, remove the converter and check it, if it has failed there will be a gray powder that will fall out and the screens may be burned out also,if any material at all comes out of the converter replace it.