1993 grand cherokee with 5.2.
New TPS, IAC, MAP sensor, 02 sensor, plugs/wires cap and rotor.

A couple weeks ago when turning into a parking spot the jeep died, several times. I got it started by pushing the pedal to the floor and drove it home. It had very little power when giving it gas. I thought I heard some light ticking from the cap/rotor area so i replaced that but it did not change anything. It starts and idles fine but when you get above 1500ish RPM's the exhaust noise changes completely ( sounds a lot quieter, makes a bit of a whine ) and the truck has no *****. It seems to shift fine. When I shut it down and restart it, it is back to its normal sound and seems just fine.. till I try to get moving down the road. I dont think its a clogged cat. I see no vacuum issues and am losing my mind on this one. NO check engine light or codes. Also when I rev the engine in park it seems OK and does not make the strange noise, though sometimes it seems slow to recover back to idle rpm's.

Strangely enough I was unplugging injectors 1 at a time and none of them changed the RPM's or sound of the engine when disconnected.

Any ideas? EGR maybe? Cam position sensor?

The reason I DONT think it is a clogged cat ( please correct me if I'm wrong ) is my muffler has a bunch of holes in it, i feel exhaust coming freely from the holes and the tailpipe. I ALSO drilled a 1/2 inch hole in the cat right where the pipe runs into it on the engine side, it did not change a thing. Transmission fluid checks out OK. I just had it up to 60, when letting off the gas, it basically sounds like engine braking on a semi then the truck goes to sounding the way it used to and has some power till I speed up again and the tone changes and I lose power. It seems to be shifting at its normal points, just takes more gas to get it there.

Thanks in advance. I usually do OK with diagnostics but this one is killing me slowly

 

What does your scan tool tell you?