Did you replace the Lambda ? this could be affecting the emissions and the idle, did you clean the IVAC too. I replaced the plugs (platinum NGK) leads with magnecor, distributor cap and Rotor arm, coil, fuel filter, air filter , Lambda and CAT and my idle is perfect steady at 800rpm (i am using super fuel BP ultimate, Shell V power or Momentum, 4500 miles on and she is still perfect.