Nissan Repair: 2000 Nissan Maxima SE, nissan maxima se, nissan maxima

Question
I replaced my EGR valve, I replaced my IACV bought one from dealer. My car starts up but its surging up and down? Do you know what might cause this or seen this happen before. I don't think its a intake gasket leak or vaccuum hose because its at a shop right know and i think they would of probably found that out by now. Ive read that these cars have a problem on the harness where it bends over the strut in engine compartment. I have also read that these cars have electrical motor mounts that been known to short out the ECU. Are these things possible because i think am gunna unplug the motor mounts once I fix the problem. If ireplace the ecu do you have to take it to the dealer to reprogram so my keys will work. Is it possible to find out whether your harness or ecu are bad so you don't spend this kind of money on guess work? I just would like your input.

Answer
Al,

I know about the motor mounts and have replaced them on my 2000 Maxima.  I have not experienced the harness problem you describe.  The surge issue after replacement of the IACV could be due to a dirty throttle body.  The passages get carbon buildup and this prevents proper operation of the IACV.  I would check this first.  Also, the manifold absolute pressure sensor provides information to the computer to make adjustments to the IACV.  Check these out and email me back.