It will idle a bit rough but will not run over 5 to 10 mph. on 1999 Isuzu Rodeo

It started running rough and now won't run more than 5-10 mph. It seems to have a dead spot in the throttle and have changed the TPS sensor even though ALL sensors are reading good. It cranks and idles a little rough and it seems to only get gas at idle and at full throttle. Any suggestions?

Asked by for the 1999 Isuzu Rodeo
Do you have check engine light??
No check engine light and ALL sensor read good! I have heard some talk of the "Power Reduction" light or button cause similiar problems....but, I really don't know what to try next.
Have a mechanic to unbolt the cat converter see if it makes a difference
Something is clogged on your exhaust system
Have already done that. The converter is not clogged.
Okay do a compression test each cylinder then
Already tested, all cylinders good
What's the psi?
Not sure. My mechanic did it last week....said all where good. Only has 112,000 miles on it. Enigine was in great shape when I purchased it a few months ago. My mechanic checked it out before I purchased it. So far, we have ruled out, blown gaskets, converter, TPS sensor, cracked block....etc.
What about do a fuel pressure test?
Dropped tank, blew out the fuel lines, replace fuel filters and verified fuel pump pressure. Lmao....been there....done that. I'm at an impasse.