I just did a change oil and then change spark plugs (from normal copper to platinum if that matters) and high tension wires for my Protégé 2000 Mazda Automatic Transmission.
Prior change my idling RPM is at 1000 and when I turn on the AC, it drops at 900 with slight vibration. After the changes, both idling (with or without AC) are at 800~900 RPM but both have slight vibrations now.
Is this ok or normal? Do I need to have the mechanic adjust the idling slightly up (is this even possible)? Or what is your opinion regarding this? I'd like to remove the slight vibration on both idling if that is favorable. Or are there any other thing I need to have check?