Update: After resetting the computer, my scanner now works, I'm only getting 1 Error (P0300: Random cylinder misfire), and I still have no power. In fact, my yard is sloped, and I cannot make it to the top of my yard, the truck backfires and sputters then comes to a dead stop. But now at idle I can rev it to 4500rpm before the rev limiter kicks in. Also Idles smooth since replacing the TPS. Maybe warped or cracked heads? Is there any way to test that with my scanner?

 

Check your oil for water contamination or your exhaust for coolant burn.
You can do a compression test on each cylinder and depending on the extent you should see one or more significantly off from the rest.

Pull each plug one by one look for discoloration or other tell tail signs of a problem.

If the truck had been sitting for a while is there any chance the parking brake is seized?

 

Oil is clean, plugs are clean, compression is good. Parking brake works fine, I can coast down hill freely. I don't want to accept it but it's really starting to sound like the transmission is shot... I thought I would have gotten an error if the transmission was acting up but I suppose that's not always true. I'm going to try removing the catalytic converter tonight, If that doesn't change anything, it's going to the garage for a tranny rebuild.

 

Sounds to me like that '06 never got a lick of maintenance. The 545rfe is a pretty solid tranny, but of course if it was ragged on or still has the original fluid it could be bad.

I'd look more at the solenoids first.

The 4.7 doesn't rebound well from an overheat, so the oil being free of coolant and compression sounds promising...

 

This is the first time I've ever tried this, but I lifted the rear of the truck up and put it in drive, then gave it some gas. It runs smooth, rear wheel speed responds to RPMs. I put it back on the ground, and it barely moves. When I have it in drive and I'm not moving, when I turn the wheel, the pumps squeaks insanely loud. But once I step the pedal down it stops squeaking. The truck is 700RPM in drive at dead stop. When gas is completely floored, it will reach almost 1500RPM Also, brake fluid is good, brake lines are bled.. however, very weak brakes. I have to floor them, It's like the power booster isn't even working. I found a vaccuum leak back behind the throttle body, I could only reach it from under the truck and I couldn't see it at all. It seems like the brakes and steering squeaking got much worse after I reconnected the 1" hose. Is this related to the no power problem?

 

I put the plates on the truck and drove it down the road, and it actually got up to speed, It seemed to shift like it should. The only problem that I notice is that it shifts from 1st to 2nd, then back to first again. But I have the pedal to the floor and it shifts to 2nd at about 25MPH or 3000RPMs, so I imagine it's just kicking back down to give me some RPMs. Then it goes to 3rd and 4th no problem (it shakes and rattles like hell), I only took it up to 55MPH on a back road. And my brakes work once I start driving! I still have no idea whats wrong but now I am assuming the tranny is fine. I'm going to get a new Mass Air Flow Sensor tomorrow. My garage told me that is most likely the problem, but they don't do much work on newer cars so it's more like an educated guess.

 

After replacing the TPS did you do the sensor reset as I described earlier?

 

Sounds like a clogged converter with the hissing and no vacuum to the brakes. You could pull the upstream o2's (before the cat) and see if that helps.It will give the exhaust somewhere to get out if the cats are clogged. Course it won't run the best for long without a reading from them(o2 sensors) but I should help see if they are clogged. If it doesn't at least the exhaust isn't hacked.

 

I Did reset the TPS sensor.

My thought on exhaust was, shouldn't it bog down when I rev quickly in neutral if the cats were blocked? I was going to pull the O2 sensors, then I decided it was just a waste of time since the truck idles perfectly fine. But at this point I suppose it's worth a try.

 

Sounds like your O2 sensor. Or a plugged cat converter to me.
It will idle smooth then get very rough and lacks power and also will sound like a miss and a hissing sound. I had a dodge that did that years back and I took out the O2 sensor and cleaned it in gas. Ran for awhile until i could get a new sensor.