+1 to what Arde stated.

 

oh ok i went out and pulled the o2 and let it run for a few and that made things worse so that cant be it

 

If you haven't yet, pull the idle air control valve. If its bad pull the intake, clean the hell out of it and the throttle body, replace plenum gasket as necessary. Put it all back together with new IAC valve and test.

 

did that but not changed the plenum gasket yet dont wanna go that far cause it doesnt appear to be leaking yet

 

it idles fine in park and will rev all it wants but if you put it in drive and drive it it will bog down around 1200 and up, so i wont drive it but around the block

 

Keep the info coming I am having the same problem. I have changed cap and button, plugs, wires all wrapped in plstic loom and routed properly, rear o2 replaced,pulled tank to check for dirt, going to pull fuel injectors tomorrow.

 

Bogging down is a symptom of clogged cat.

 

ok, Im going to chime in on this. I traded this truck to Chris about a month ago. (REASON BEING, I HURT MY BACK AND COULDN'T WORK ON IT ANYMORE ) Personally i liked that truck..

when I traded it, I had bought a NEW IAC for the truck and 02 sensor. after installing the IAC valve and trying to get the old 02 sensor out (which i didn't get out) It seemed to idle correctly. I never had a problem with the truck driving normal or on the highway etc. I used to drive it 60 miles a day. The symptom it DID have was if you mashed the gas pedal it would start popping out the exhaust around 3000 rpm..and it had a crappy idle when warmed up.. but i got it to idle correctly after replacing the IAC valve.

But besides that it ran fine and idled fine, even at the time of trade. And he was aware of the problem of it not going past 3000 rpm if you floored it.. well it would surge and buck and pop out the exhaust.. but if you let up slightly on the gas it would go. I even drove it to meet him 1/2 way (20 miles on the highway)

Now i don't know what would have caused it to not drive past 1200 rpm now..
could be clogged cat , looks like he redid the dizzy with new plugs and wires..could be out of time? could be plenum gasket.. but the symptoms i was getting weren't matching to plenum problems.
Anyways, thought I would put this up to try and help out and narrow down what could be wrong.
If pulling the 02 sensor complety out didn't help.. Id look into making sure it's timed correctly. Just odd it idles fine, and you can rev it fine... but when you drive it and doesn't go.. ?????

 

Check fuel pressure at the rails to the injectors... could possibly be the injectors or not enough fuel pressure ???

 

the fuel injectors are good, idk what the new problem is but its seriously annoying ive got alot of work pilling up and need my truck to do it