LoneStarr404

Hey,

Im having a few problems with my 1993 pickup with a 3.4 that I recently purchased.

The first problem is it idling high. It idles at about 1100 most of the time. Other times it idles fine and I can get it to drop if I turn on the AC (which does not work). On a cold start it will idle at about 1500rpm for a couple minutes the drop down to about 600 for a second stumble and the jump up to 1100. Sometimes it doesnt do that and just goes from 1500rpm to 1100rpm

Second problem is it misfiring after driving it for extended periods. It will loose power and stumble. This seems to get worse the longer I drive it. Sometimes it just wont go over 3000rpm on the highway.

I have replaced the air filter, plugs (denso dual electrode) and wires. Also cleaned the MAF, throttle body, and IAC valve.

I cant get an ob2d scanner to read anything. It has power to the connection but it wont take a reading. I tried two separate scanners. I assume this is from when the swap was done.

I'm hoping for more options to troubleshoot this problem before I just start throwing parts at it.
The exhaust on the truck looks pretty beat up. Could a bad catalytic converter/leaks in the exhaust be causing these problems?

Thanks in advance