ok so i have a 2000 honda accord lx with the 2.3 liter inline 4 with vtech. 131000 miles 5 speed manual transmission. i bought it mid december 2010 and it had a vibration only at idle. Recently, I had the alternator (only pushing 11-12 volts) and all 4 spark plugs replaced. my mechanic told me that this should take car of the vibration. the vibration has gotten better, even though it isnt completely gone, and i noticed that the engine runs quieter and smooth as well as having more power. the vibration only occurs now when its under 1000 rpm and i turn on the ac, or when i turn the steering wheel, or hit the power locks. i notice the rpms temporarily drop by maybe 50 when i do anything mentioned above. any ideas?