Hi, I have an 87 4runner EFI I have had some problems with it running rich. I changed the plugs, wires, cap rotor, O2 sensor, and had the timing corrected. I have noticed that my idle is somewhat inconsistant. It will idle high upon startup which I assume is normal but then once it warms up it will idle anywhere between 600rpms to 900rpms is this normal? I was also wondering what sorts of mpg I should expect for city driving? If my problem is TPS related how difficult are these to replace out?

Thanks!