No Power, Help Needed

[polarisman]

I know I don’t post on here, but I am always around reading posts and such (I don’t have much knowledge to share so I just read!). I can usually find the information I need from previous posts, but not this time. So if anyone has any advice please let me know.

I have a 2001 sport trac 4.0 sohc auto, 90,000 miles. The other day on the highway I was going up a pretty good grade and had her working hard when I suddenly lost power. I made it home at about 40 mph, with no power to accelerate more. Now it is in my garage it starts and idles fine, but if you hold down the gas pedal it will climb to about 3k and then quickly start losing power and the rpms will go down to about 1k and the truck will just sputter. If I let off the gas it will sputter some and then start idling again. That is about it for what to describe with the problem, no new codes. I say this because I have had a gas cap light for about 2 years and when the dealer fixed it, it came right back on, so it has stayed on since.
Put in new plugs and wires, air filter, fuel filter, tested the coil, tested and cleaned the IAC. No change with any of this. The cracked elbow was also replaced long ago.
Thanks!
I guess I will post this later, since we are having crazy wind right now and the power went out, no wireless… Power in the house this morning, house is down to 55, so much for May.

Thanks!

 

[polarisman]

So tonight I was going to drive the truck some to get the exhaust hot. I was told that it might be the cats and once they got really hot I might be able to see the glow if the cats are bad. Well once I started it, it started quickly and idled for about 3 minutes. Then I went to drive and it died. So now it would seem that if I start it cold it is fine, but once it starts and runs for 2-3 minutes it dies. Once it cools it will restart again fine.

I am thinking perhaps an exhaust blockage?