Since the answers to my previous post, "Symptoms of Bad Crank Position Sensor," lead me to believe that the CPS is not the culprit, is it likely to be the Throttle Body?
Again, the list of symptoms and fixes so far:
1. Surging idle once warm, reduced by putting the auto in neutral while stopped at lights. Mostly annoying/stressful, but does not cause the car to die.
2. Hesitation during 40+ MPH hard acceleration -- not due to auto downshift delay
3. Slight low-speed knocking as if timing is off. One possible explanation for this might be replacement of colder NGK 7ES plugs with multi-range NGK 6ES.
4. Poor power, as if timing is off
5. Smoke on full throttle acceleration, sometimes
What has been done to eliminate the obvious:
1. Cleaning of throttle body with carb cleaner
2. New plugs, see comment above
3. Oil change
4. Injector cleaner in gas
5. Relacement of hard vacuum hoses
6. DI Cassette replaced within last 15K miles