Chrysler Repair: 1994 LeBaron GTC 3.0L, wont idle, lebaron gtc, vacuum leaks

Question
Son overheated his 40,000 mile GTC, warping the heads.  After resurfacing the heads and replacing valve guides, water pump, timing belt and gaskets, it is up and running.  Well almost.  It will not idle.  I noticed the fan was not coming on and the motor was getting hot.  So, I jumped the terminals on the temp switch to check it. The fan came on and the temp dropped.  Thinking that this may have been the cause of the original over heating and maybe the reason for the computer not being able to hold idle, I replaced the temp sensor.  Now the fan works correctly, but the car still will not idle.  I pulled the rubber plug out of the extra vaccum port at the EGR connection to allow more air in and the car idles fine. However, this has given me an engine code that the EGR is not working correctly.  By the way, it is also giving me the "Bad Temp Sensor" code.  Do I need to replace the other temp sensor also (the 3.0 has 2)??  I was under the impression that the other, single wire temp sensor was for the dash light only.  Any ideas??  

Answer
Hi Wayne,
You may just be looking at stale codes: disconnect the battery for a few minutes to erase all the codes EXCEPT you will find that it then sets a code 12 (battery disconnected recently) which can be ignored. Then drive it and check for fresh codes.
There is only one temp sensor that affects the engine performance. The other sngle wire one is for the gauge/light on the dash. I would check all the vacuum hoses/connections using the underhood sticker as a road map. Any leak will dilute the mixture and cause rough idle.
I am not clear which vacuum hose/plug you pulled. But the mixture is probably the issue. You would do well to check whether the egr valve is closing tightly via the spring action, using the slot in the stem to lever it back and forth against the spring action in one direction, and using the tip of a screwdriver in the slot to move it. Also check for vacuum leaks around the intake manifold using spray starter fluid to note any changes in idle speed. A vacuum leak, a partially open at idle egr, or a cracked/disconnected vacuum hose are sources of dilution of the mixture.
Roland