revs high p0507, p0131

I have a 97 Blazer 4X4 with a 4.3 The truck had a high idle, and it was hard to stop, also it would take about 3-4 seconds to get the drive gear to engage and I was pulling the codes P0507 and P0131, so i bought a new idle control valve and installed it. When I first started the truck the RPM's reved way but it did come back down to a some what normal idle, when shifting in to drive it went right in and all seemed well, but now the truck is running like crap, here is what it is doing and I'm getting the P0507 and P0131 again.


when I first start the truck the idle revs up and comes back down
I wait for the idle to come down before shifting in to drive and after I shift in to drive it revs back up and then comes back down
While drive at 80kph I can take my foot off the gas and the truck stays running at 80 cause of the high idle.
While driving if I put the truck in nutral it revs up, if I give it a quick shot of gas to get the RPM's down they go higher and stay there till i pull over and come to a complete stop.
When i come to a stop light or sign the truck is running at a high idle and is hard to stop but after I stop it will come back down after 2-3 seconds.
Was there something i should have done with the ICV when I put it in. What can I do.

did you replace the bad o2 sensor? if it isnt getting a good reading, the engine wont be able to adjust fuel trim and timing.

also, make sure your pcv valve (and any other vacuum lines) are plugged in properly. I just recently learned that leaving the pcv valve disconnected will cause a high idle and a p0507