No power, hesitates, wont rev

I just bought another Mustang with 1k miles on a rebuild. The car has NO power at all! Will barely spin the tires. If you get on it, it wont rev, and sorta hesitates/misses. If you rev it in neutral, it wont go above 3 or 4k RPM, like it has a rev limiter.

I've checked the TPS, key on engine off I get .96 with a nice linear scale to 4.6.
Fuel pressure is @ 30PSI idle, with any throttle given to it it goes to 40PSI.
I have not done a volume test on the fuel system, nor have I checked the TFI.

Anyone have any suggestions for what to check next?

Oh yea, I have one code, 54. I unhooked the ACT and grounded the connector, but did not get a code for the sensor being grounded... So I assume bad wiring. Could this be related?

BTT any ideas?

Oh yea this is a speed density 2.3 but the same mechanical theory applies.

Timing is at 12. Cam is advanced 4 degrees.