Honestly makes you somewhat appreciate coil-pack equipped cars with mass-air flow sensors and built-in diagnostics. If it doesn't run right, you plug it into the computer and it tells you what's not right. If you can't figure that out, look further at adaptations and see what the car is trying to correct for. There are some trade-outs, but there's no reason for a 2000 or newer car not to run right (unless someone puts black tape on the instrument panel to cover up all the lights, but that's another story).