Supra throwing codes 42 and 51. 42 is the Speed Sensor, because the adapter for the speedo that plugs into the tranny is broken (SURPRISE!). That's only an $85 and 40 minutes on your back fix. Of course, a lot of other things would start working if I replaced it.
Code 51 is AC pressure switch. OK, it's R-12, there is NO refrigerant in the car, but what, if any, effect does this have on drivability that makes it show up in the ECU?